Our welding table that we built a few years back was starting to look kind of small, and we wanted to make something a little more versatile. There are a few companies that build tables with holes all over the surface for specialized clamps, but we didn't want to reinvest in all new clamps, since our work just fine, and we have a lot of them! Plus, regular clamps are a bit cheaper than specialized welding table clamps. So, rather than holes, we made a bunch of large slot cuts all over the surface to allow for standard clamps to clamp to the table.
The entire table pops together using tabs and slots, and it practically assembles itself, minus the welding. Since all the parts are cut on our CNC plasma cutting table, the table also self-squares itself and welds together very flat.