This is a beautifully cut hyperbolic paraboloid, one of the most classical mathematical shapes. Hyperbolic paraboloids are covered by straight lines which makes them well-suited for applications in architecture, some of which are shown on this object. MO-Labs also provides the same object without any straight lines shown: https://www.shapeways.com/product/T9ECQBQ8R/a-hyperbolic-paraboloid.