So how to make a game table in ten minutes? This stuff.
Before and after pics...
I wish it wasn't quite so narrow, but I might be able to help that by just painting the pull out flat panels as well. I made a test sketch of a dungeon from Knockspell #3. I see using this more for quick sketches than drawing complete maps, and building interiors would work especially well.
It's probably a little cheaper than a battlemat, although you'll have to bust out the ruler for distance measurements. I might put some thin lined hexes or squares on it with paint or fine point white sharpies. You could paint a very large area with one quart - the can says about a hundred square feet. Plus you'll have something the kids can play with and can use for other games or practice their math skills on. I recommend using foam sponges for laying down the paint - coarser brushes may leave slightly raised streaking.