Machine Design files have a .md extension. In these types of files you design solids that collectively represent a CNC machine and specify how these solids interact or move according to how your machine operates. (You must have the ability to at least import solids, that is, you must have the solid import plugin installed which comes with the FeatureRecognition product, the 3D milling product, and the advanced solid modeling product).
Each solid represents a particular part of your machine, and it is important that you model each movable part of your machine as an independent solid. That is, do not make use of the solid wizard's Combine Solids command to union two tables into one solid, because you need to rotate one table independently of the other. If you have imported a file and it contains only one solid, use the Explode Solid method and then reconstruct multiple solids from the exploded surfaces (probably constructing additional surfaces as well).
In an MD document, there are no manufacturing-like commands. That is, there is no stock, no Setups, no simulation, and no manufacturing attributes, manufacturing menu, and so on. The purpose of the document type is to design solids, and to assign attributes to the solids that match your particular machine movement and machine hierarchy. An example of a machine hierarchy is that tableA is on top of tableB and so, whenever you rotate tableB, tableA is also rotated. This is called a parent/child relationship.