Reply by LittleShaver

For my assembly tables, I use your first design and top them with damaged hollow core doors with a couple of coats of shellac. Deck screw hold everything in place except the tops, they stay in place with gravity and added blocking on all four undersides to keep the tops from shifting about. I picked up the doors for next to nothing at the local Lowes in the back corner. I have two that have been in service for about 9 years and have had no issues with racking, weight carrying ability or stability. The only problem I’ve ever had was overloading one edge and having the other lift up. A clamp fixed that transient issue. I did add levelers to both tables so that I can use them for out-feed tables when needed. My garage floor is far from level as are most.

-- Sawdust Maker