I second what Italophile said. I'm new to VBA, but that was some advice I read early on. Especially if you share your modules to others, as you want to leave normal.dotm alone as users may have recorded macros that are stored there.

I just made my own .dotm file, and store it in %appdata%\Microsoft\Word\STARTUP so it loads when you start Word.

If you want to upload a Word doc with your tables that have the problem, as well as what it looks like after it's fixed, I can look at it and see if I can get it to run faster.