What would I like to see?
A double-layered table with the layers about 10-12" apart, where the lower layer is an ordinary table (for drinks, character sheets, dice, etc.) and the top layer, overlaying all but about the outer 6" of the lower layer, is a chalkboard with a 2" grid permanent-inked onto it. The chalkboard layer would be hard-attached somehow, but also be removeable to allow full access to the lower table layer for cleaning etc.
We've used chalkboards for 25+ years - they really are the answer, and a bit of chalk dust is so much more preferable than the horrible smell of those dry-erase pens.
2" grid (for 10' squares) is preferable to 1"; less squares to count means less chance of screwing it up. Were I to go with 5' squares I'd probably want them to be a bit bigger than 1" just so things would fit.
Lanefan