In this example of a hyperboloid table - I used a T-Spine to help create the hyperboloid shape that defines these kinds of structures. Sure - there are other ways to do it, but they often entail 3D Sketches and take time and effort - while using T-Splines can make it fast, and easy. I often use helper geometry in this way to save myself having to create extra sketches....I hope you find it useful!