i use a table too.. It's higher though, with bricks under the feet it is about 29 inches high in the front (where g25 is attached) and about 27.5 inches in the back. It's a 24 inch table naturaly, with 2 regular red building bricks under each foot. I have it shimmed up in the front (toward me) - that way the wheel is angled up a little because the table is tilted slightly up towards me. The tilt isn't totally necessary, but it helps to dial in the hight and tilt of the wheel.
That way i can use a regular kitchen chair or office chair or whatever. I use a comfortable kitchen chair that's about 17.5 inches high at the seat. I have a foam cushion that raises that by about 1.5 inches when compressed. It's very comfortable for long racing sessions- the chair even has armrests. After an hour or so armrests are pretty important -to me anyway, but i have a messed up left shoulder.
Anyway getting to the point... If you want to give your table a super sturdy and stable feel, nail the feet to the floor.. No just kidding, ;-) but if you want it to almost feel like it's nailed down, find a heavy weight to put on the table right in front of the wheel. If it's a metal plate weight for weight lifting it works well with a rubber mousepad or something like that under it to protect the table and keep the weight from sliding around.. I have a cylinder of steel that i found that's about 5 inches in diameter and 4.5 inches high that weighs about 27 pounds. It might be iron actually, it's really heavy for it's size.
This weight gives a very solid feel while sawing at the ff wheel with ff cranked up. It really doesn't move much at all, and if the table ever moves it's when i put direct upward pressure against forcefeedback. Even then it might come up only a fraction of an inch on one side and come straight back down. In two years i've never had an issue with anything shifting around too much or anything tipping over, etc... And i race just as hard as i would with a cockpit with everything bolted down.
Something to try for all you table racers out there if you haven't already thought of it.