It's actually not a welding table. It's really an
optical table. Three of them were donated to our school, we took two and sent the third to another local team.
Since it is an optical table, it's close to perfectly flat. The legs are also designed to isolate the table top from vibration. The table top is about 5' x 12' with 1/4-20 tapped holes spaced every 1". This makes an ideal surface for welding frames together since we can lay parts flat, clamp and jig them up with the 1/4-20 mounting holes. After welding we can also use the table to make sure the aluminum hasn't pulled too much and if it has, correct it.
Since the tables were donated, I can't tell you where they were purchased or how much they were. I did some research and found one that is the same size for about $6,900 on eBay. The table is not light. If you're interested in purchasing one, find one near by and rent a truck and fork lift to move it.