A couple of thoughts that may help:
1) set up a table style that contains the fonts, text sizes, cell styles etc. that you want, then use that table style when creating the data link about table styles this will eliminate scaling issues later, since the table is the size you want
2) place the table in model space, then use VP scaling in paper space to display the table at varying "sizes / scales" for any scales you need other than 1:1
3) for each data link you need to use, create and use a named range in your excel file , then link your table to this named range. If you need to add rows or columns, insert them into an area within your named range, then edit cells as needed. This will ensure that the data link to AutoCAD will remain valid. The table may still need tweaking to get all to look right after an update, but the link should remain connected. Set up all formulas, calcs, etc. in Excel, and convert data formats to text in AutoCAD, this should ensure a consistent text display in the dwg table.
This method works well for me, and has for quite a few years now. Hope it helps you out.
