If you like to host large dinner parties but don't have an especially large family you may be interested in this project. Instructables user falk designed and built a formal dining table that can comfortably seat 10 but folds down to the size of a couch table.
When you take off the removable legs you can fit the entire 10-person table in your closet. The author provides Google Sketch-Up files along with step-by-step photos and instructions. It will take a weekend or two to construct and depending on your construction skills and the base materials used, it will cost somewhere between $US100-$US200. If you build your own table legs or buy them pre-made and how crazy you get with decorative trim and staining will also affect the price.
I like how the whole thing folds up to fit in the back of your average car. I can see this and a set of nice stacking chairs making a portable holiday kit.