It can be a little confusing, but just think of the MPRM1 as the Building or Area that holds the MAPTBL1. You could use a Hanger if you wanted to.
You need the MAP TABLE if you want to see the terrain map. Try replacing the MAPTBL1 shape with a 20MM shape and you'll see what I mean when you go into the MapRoom in the game.
You could remove the MPRM1 but it wouldn't look good.
Pokie