looks more like an assembly table then a fabrication table
assembly tables dont need to be any more level then jackstands on the ground would be
im going to assume that the bare chassis, which is already fully welded, will be set on this, everything test fitted, adjustments made, parts modified, and in the end the car will be lifted off with maybe a 2 post lift
the wheels are there so the project can be pushed out of the way during business hours, something that would be impossible with jack stands or a car hoist