Here's a shot from a batrep I did last year. (My Marienburgers on the right, the newly released Dark Elves on the left.)
My table is themed about as far away as you can get from a desert. It's swampy. Unless otherwise agreed upon, the entire table counts as open terrain. Only the movable terrain items (the hills, woods, ruined building, etc.) have any terrain/game effects.
A desert table would probably be simpler.
It's made on four 2'x4' sections that can be put on my dining room table (as it is in the pic.)