Yes ! the classic waffle structures , I think this kind of definitions are very useful specially to those starting in their way of parametric design and of course Grasshopper, they have a wide range of applications that can go from architectural projects to conceptual furniture like this quick example I made.
The definition is made so you can set up the number of sections in the X and Y axis separately , also you can set up the height of each sections as well as the thickness of the material you are going to work with. Finally the definitions orients al the parts to the X-Y axis with an ID tag so you can easily organize them and get them ready for the CNC mill or the laser cutter.
This definition will help understand most of the basic components that Grasshopper currently has implemented,It was made with Grasshopper Version 6.0019 we have to remember it still is a WIP so they maybe some problems using it in other versions. I strongly recommend you to download both files the grasshopper definition and the rhino file so you can get familiarized with the inputs you need to start working.
Rhino file: Ribs(WaffleSystem).3dm
Grasshopper DefinitionFile: Ribs(WaffleSystem).ghx