How about using reinforced concrete for a table's frame?
I've seen welded square section pipe and aluminium extrusion being used so far.
Reinforced concrete would be very cheap and very strong. The mold could be made with MDF boards and the whole thing could be designed to bolt together using studs burried in the concrete.
The automation would could be supported by studding burried in the concrete, so that it could be leveled and locked in place once fitted.
I would also be interested to hear what size tables everyone is using, what form of automation & guide ways and what they think of the combination.
Best wishes,
John