These are some computer lab tables that I made. There are ten in all, and each table will accommodate three computers if the towers are on top (as shown), or four computers with the tower stowed under the table.
It is a simple construction of 3/4 " Burch plywood and Formica for the top. They are eight feet long 29" high and 30" deep. The backer board is 18" wide and is attached 8" from the back to lend support and it provides room for the cables and power strips that are attached to the back. I also put three 2x2 supports going from the backer board to the ledger board.
You could go with any dimensions really I just wanted to fit in as many computers as possible. With the long span I opted out of the usual MDF for the top because I was worried about sagging. I also added a 1 1/2" piece of Aluminum flat bar to the back of the ledger board- this provided quite a bit of rigidity to the front edge.
If someone were to make a few tables like these it wouldn't be too complicated. The only complications I ran into were due to the fact that I had to make ten of them and didn't have much space to work with.
Thanks for looking!