I would use a rivet nut, which is basically a nut with some rubber around it that expands when compressed. Basically, you drill a large hole in the wall (say 1/2"), press in the rivet nut, and then screw in a machine screw attaching the table. As the screw goes in, the rubber expands behind the hole, preventing it from coming out.
I've used them for this very application and it has not since budged. Apparently they are used to mount roof racks to cars.
See:
http://www.mcmaster.com/#catalog/121/3309/=10junbz
Look at part 93495A111 -- Rubber-Insulated Brass Rivet Nut 115-Piece Assortment in Plastic Box -- it's a big assorted box of them. But you can get smaller quantities for less money.
Dave