The blue out line, are tables, here we assume 2 pushed togther along their longer side, they could be set in the middle of the room or the middle of a wall so that people can stand on 1 of 3 sides.
The door/bay sections and parking lot/mountain side are set back from the edge of the 'front facing table.' This is so that 6 inches or less of material can be added to the 'front' of the bays/parking lot, breaking up the long striaght edge of fromed by all 3 sections (6 feet long).
Tony mentioned chopping the edge of the bays to do this, but at the last buildfest we had stuff right up to the edges of the bays. Also we couldn't do this with the door sections, they go right to the 'back' edge (the front of the door).
By adding a bit of material to the front of the doors we can have a little scene going on there, and join the mech base to a mech or two standing out front, 'floating' on hexagon bases. This reinforces that these are scaled up gaming miniatures, and this is a gaming board layout.