Waffle Brown Concrete Slabs
It is a grid of waffle-shaped concrete slabs having a tint of brown.

The concrete color, amount of pores, intensity of dust, junctions, dirt color etc. can be manipulated by the Substance SBSAR file.
 
Concrete Waffle Slabs
From the grid pattern, we know that they are waffle slabs made of reinforced concrete. They grid pattern allows concrete ribs running in 2 directions perpendicular to each other on its underside.

As it appears in public area, dust and dirt can be found on the surface. Besides, there are imperfection at junctions between slabs.
Spongy Waffle Texture
It is a waffle material having spongy like texture. The batter is airy and fluffy. It is an incredible map for texturing baked waffle.

Small and large pits can be found on the airy surface. These are the result of a bake.

Since a cake is organic, please remember to enable specular and scattering in your shader in order to achieve a perfect render.