When decking Mianne benchwork I like to use 5' X 10' panel material. The sides can be ripped back several inches for an even overhang or sculped to accommodate cosmetic curves. I prefer to cover the benchwork frame top edges.
Many lumber yards can get 5' X 9' or 10'. I believe 5' X 9' is standard ping pong table material.
I used 5' X 10" by five quarter decking for my gluing and clamping assembly tables. They made a nice L shaped train table when I closed shop.