I scored a roll around work table next to a dumpster and it's so stable that I'm taking the melamine top off and welding upright I-beams to it for a welding table. The footprint is close to 4' square and the top is around 36" off the floor.

I also built a wooden stand for my mini-mill and the footprint is around 30" square and each leg is slanted inward at a 10º angle towards the center so that as weight is added to the top it becomes increasingly more stable and rigid. Works good.