He is saying wants to create a 10 x 30 map similar to the boards in squad leader.
Most games use more than 1 board so you are going to be cut & pasting anyway so I would make all maps 30 x 30.
Going to need to create 4 for each board to cover all facings, then there are the overlays
For multiple board sets load the first board
Adjust playing area to total size for all boards, 40x30 would be 4 boards.
Cut & paste the other boards to original board.
Done.
Dont remember playing many single board games, would need to get creative & while not perfect just add a couple of rows of impassable terrain.