Just about anything that will get you up out of that monkey squat position will do as a welding table, one of the best is an old sheet of ply wood sitting atop a couple of 2 x4's on sawhorses, need a grounding surface lay a sheet of some knid of metal on it....it is cheap and can be taken down and stored out of the way. One advantage of a wooden table is you reduce the possiblity of a zap when you rest on the wood surface another is,,,being able to screw down pieces of wood to help jig up or frame up the metal you are welding,,,,when you finish just unscrew the wood strips from the plywood,,,it's just an old piece of scrap plywood so you don't worry about making holes in it.
I have other tables,like an all steel one 2' x 3' with a 1/4 inch top on wheels with shelves and a vise mounted on it, but it is heavy loaded with all the junk a fellow puts on them....
The sawhorses and old plywood works pretty good,,my latest efforts are a couple of pieces of 5/8 inch plywood 33" x 40" with a couple of those folding sawhorses bolted to it,,,,it is cheap ,,folds up out of the way,,,but even so each one still weighs 30 pounds...
Bottom line: what ever gets you up out of that monkey squat position and sitting in a chair is a welding table to me.
Some of those lies people tell about me, are true