The top is 3/4 MDF and its a single sheet of 4'x8'. Technically I believe a true ping pong table should be 4.5'x9' but it would have taken up more space and required 2 sheets of MDF to do. For just having fun I think my table works fine. The frame it sits on is 3'x6' , made from 3/4" thick 3.5" wide pieces of plywood and the legs are 29.5" long. My frame is probably a little ridiculous I tend to over build or over engineer things. But the goal was to also use up as much material as I could so I didn't have a bunch of scraps.
4'x8'. Proper table size for ping pong is 4.5'x9' is I remember correctly. But 4x8 was much easier to do, I had the materials on hand and it fit better in the room.