I was looking there but it didn't seem like the one. Must be this block. Not clear which line(s) to comment out. There is a single "Parts" table on the CAD Doc Related Objects page.
<!-- Information page 3rd level navigation Related Objects menu options -->
<model name="relatedItems" resourceBundle="com.ptc.core.ui.navigationRB">
<description>
"Related Objects" 3rd level nav menu
</description>
<action name="relatedCADDocsCADDocuments" type="part"/> <!-- CAD Documents -->
<action name="relatedPartsCADDocuments" type="part"/> <!-- CAD/Dynamic Documents -->
<action name="relatedPartsDocuments" type="part"/> <!-- Described By Documents -->
<action name="relatedPartsReferences" type="part"/> <!-- References Documents -->
<action name="relatedDocumentsDocuments" type="document"/> <!-- Reference Documents -->
<action name="relatedDocumentsReferencedBy" type="document"/> <!-- Referenced By Documents -->
<action name="relatedTranslations" type="translation"/> <!-- Related Translations -->
<action name="baseLanguage" type="translation"/> <!-- Base Languages -->
<action name="documents" type="supplier"/> <!-- Documents -->
<action name="relatedWorkSetDocuments" type="workSet"/> <!-- Documents -->
<action name="relatedPartInstanceDocuments" type="instance"/> <!-- Documents -->
<action name="separator" type="separator"/> <!-- ====================================== -->
<action name="relatedDocumentsParts" type="document"/> <!-- Parts -->
<action name="relatedCADDocsParts" type="part"/> <!-- Parts -->
<action name="relatedDocumentPartInstances" type="document"/> <!-- Part Instances -->
<action name="parts" type="supplier"/> <!-- Supplied Parts -->
<action name="separator" type="separator"/> <!-- ====================================== -->
<action name="alternates" type="part"/> <!-- Alternates -->
<action name="alternateFor" type="part"/> <!-- Alternate For -->
<action name="substitutes" type="part"/> <!-- Substitutes -->
<action name="substitutesFor" type="part"/> <!-- Substitutes For -->
<action name="separator" type="separator"/> <!-- ====================================== -->
<action name="variants" type="generic"/> <!-- Variants -->
<action name="variantspecs_all" type="generic"/> <!-- Variant Specifications -->
<action name="variantspecsofvariant" type="variant"/> <!-- Variant Specifications -->
<action name="separator" type="separator"/> <!-- ====================================== -->
<action name="singleLevelTraceability" type="object"/> <!-- Requirements Single-level Traceability -->
<action name="TraceabilityLinksTable" type="requirement"/> <!-- Requirements Multi-level Traceability -->
<action name="SpecificationsTable" type="requirement"/> <!-- Specifications -->
<action name="separator" type="separator"/> <!-- ====================================== -->
<action name="relatedClashes" type="clashReport"/> <!-- Related Interferences -->
<action name="relatedClashReports" type="clashReport"/> <!-- Related Interference Detection Reports -->
<action name="separator" type="separator"/> <!-- ====================================== -->
<action name="traceabilityRoleBLinkTable" type="object"/> <!-- As-Defined -->
<action name="traceabilityRoleALinkTable" type="object"/> <!-- As-Designed -->
<action name="handedPartsRoleALinkTable" type="object"/> <!-- Right Handed Parts -->
<action name="handedPartsRoleBLinkTable" type="object"/> <!-- Left Handed Parts -->
<action name="separator" type="separator"/> <!-- ====================================== -->
<action name="AccomRequirements" type ="SoftwareBuild"/> <!-- Accomplished Requirements -->
<action name="relatedActionItems" type="actionitem"/> <!-- Action Items -->
<action name="activites" type="reqlObject"/> <!-- Activities -->
<action name="affectedEndItemsTable" type="change"/> <!-- Affected End Items -->
<action name="affectedDataTable" type="change"/> <!-- Affected Objects -->
<action name="affectedAndResultingItems" type="changeTask"/> <!-- Affected/Resulting Objects -->
<action name="changeSummary" type="changeNotice"/> <!-- Affected and Resulting Data for all Change Tasks on a Change Notice -->
<action name="sumaChangeTree" type="suma"/> <!-- Supplier Parts and related documents for Resulting data for change notice-->
<action name="analysisActivitiesTable" type="analysisActivity"/> <!-- Analysis Activities -->
<action name="annotationSets" type="annotation"/> <!-- Annotations -->
<action name="plan_deliverable_activities" type="planActivity"/> <!-- Associated Activities -->
<action name="associatedBuildsTable" type="softwareDefect"/> <!-- Associated Builds -->
<action name="showAssociatedDefects" type ="SoftwareBuild"/> <!-- Associated Defects -->
<action name="plan_activity_deliverables" type="planActivity"/> <!-- Associated Deliverables -->
<action name="relatedBaselines" type="object"/> <!-- Baselines -->
<action name="baselineObjects" type="baseline"/> <!-- Baseline Objects -->
<action name="context_adapters" type="scmi"/> <!-- Clearcase Adapters -->
<action name="relatedWorkSetComponents" type="workSet"/> <!-- Components -->
<action name="generics" type="variant"/> <!-- Configurable Parts -->
<action name="designSolutionEff" type="object"/> <!-- Configuration Items -->
<action name="relatedContexts" type="object"/> <!-- Contexts -->
<action name="relatedCC" type="mpml"/> <!-- Control Characteristics -->
<action name="relatedDeliverables" type="deliverable"/> <!-- Deliverables -->
<action name="relatedDesignSolution" type="part"/> <!-- Design Solutions -->
<action name="lowLevelPartEff" type="part"/> <!-- Design Solutions -->
<action name="distributionList" type="tgt"/> <!-- Distribute Targets -->
<action name="implementationPlanTable" type="changeNotice"/> <!-- Implementation Plan -->
<action name="relatedManagedCollection" type="managedcollection"/> <!-- Managed Collection -->
<action name="relatedNotes" type="note"/> <!-- Notes -->
<action name="relatedPackages" type="wp"/> <!-- Packages -->
<action name="predecessors" type="plan"/> <!-- Predecessors -->
<action name="promotionItemsTable" type="promotionRequest"/> <!-- Promotion Objects -->
<action name="relatedMPMProcessPlans" type="part"/> <!-- Process Plan -->
<action name="relatedPartsEnterpriseData" type="enterprisedata"/> <!-- Enterprise Data -->
<action name="relatedPartsLists" type="part"/> <!-- Parts Lists -->
<action name="associatedChangeAnalysisTable" type="changeRequest"/> <!-- Proposals and Investigations -->
<action name="publishedContent" type="object"/> <!-- Published Content -->
<action name="resources" type="plan"/> <!-- Resources -->
<action name="actionItemSubjects" type="actionitem"/> <!-- Subjects -->
<action name="successorList" type="wp"/> <!-- Successors -->
<action name="supersedes" type="part"/> <!-- Supersedes Table -->
<action name="contacts" type="supplier"/> <!-- Supplier Contacts -->
<action name="changeWorkItemsTable" type="changeNotice"/> <!-- Work Items -->
<action name="relatedWorkSets" type="workSet"/> <!-- Work Sets -->
<action name="separator" type="separator"/> <!-- ====================================== -->
<action name="relatedMeetings" type="meeting"/> <!-- Meetings -->
</model>
