Please work from materials that are available anywhere in the world (such as plywood and MDF for CNC milling and PLA for 3D printing. Use joints that do not require special knowledge or a unique tool without which the person can not get ready!
If you design for CNC milling the maximum size of one part can not exceed 800x800x18mm.
For your inspiration check out a project made by Tamás Deme:
release is a flat-pack desk, which can be assembled without any tools, and can be used as a dining or a conference table. The project was developed in collaboration with Fészek Részek furniture design studio and FabLab Budapest.