Mary,
Epic supports several different stylesheets, FOSI, XSL-FO and their Styler.
Each does things a bit differently though the basic premise would be pretty
much the same.
If you have a good ASCII text editor (a good freebie is Notepad++) I'd
search through the stylesheet(s) for the element <thead> (the most COMMON
element name for a table header if you are using either the CALS or Exchange
table model). Once you have found that area in the stylesheet, look for
something about alignment. There may be a horizontal and vertical option,
you'd want the horizontal.
I kind of recommend Notepad++ or other apps like Codewright (no longer
supported but still available) or Ultraedit that support multiple file
searches and regular expression searches. This makes finding things a bit
easier.
Then set the value to 'center'. If it is already centered, then you have
other problems.
If you are using a FOSI or Styler, Epic can open these files in Epic and you
can search for formatting rules and make changes that way.
Lynn