Hi
I think I have just had a "lightbulb" moment (I get them occasionally ).
You can apply table styles to tables in your document and when you insert new rows the style adjusts automatically.
Follow these steps:
1. Click inside your table anywhere.
2. The Table tab will then appear at the top of your screen.
3. Click on the Design option.
4. You will then be presented with built in styles for your table which you can select.
Hope this helps.
Good luck.
Tony