Can´t modify Note Properties

To modify the decimal places in a Creo Parametric family table repeat region, you must switch symbols first.

When the table is actively displaying the populated numbers (such as 312.700), the cells are temporarily locked from direct property text overrides, which is why your text panel text box is greyed out.

Took a little trial and error and testing.  Being a family table table, it is a 2-D repeat region, and it works a bit different.  Switch Symbols and edit the cell in the second row with fam.inst.param...

Thanks for the point, i modify the Note Properties but it seems that my table do not update. 

You may need to regenerate and/or Update Tables from Table > Data in the ribbon.

I thought you could only update decimal places by changing the actual dimension itself to whatever your choice of decimals.  You can't choose for the column to be a mix of decimal places