Tim, That module is a extra thin module. Only about 2" thick due to a roll out work station stored directly below. This is a waffle core module. Much like a hollow core door. The oval cutouts permit access for wire drops and buss routing. The module is unsupported for 6 1/2 feet but yet quite stable.
That portion of platform is in center rear with a raised / curved up front fascia. Sort of an arch of strength.
