^ I think you hit the nail on the head with that one...
More generally, there are one way and two-way slabs in addition to flat plate... for highrise construction, the flat plate is generally preferred for the flexibility it allows in laying out walls, mechanical systems, etc. For more specialized structures like parking garages or warehouses, you may see the simple one-way and two-way designs.
Even more complex configurations are possible, with waffle slabs, drop panels, and/or capitals. These have generally fallen out of favor.
