This book presents an innovative conceptual framework of Actuated Tangible User Interface (ATUI) for tabletop interactions with direct physical feedback. The framework consists of a self-contained interactive table and extensible ATUIs that give feedback in the physical form. One significant feature of such an interface is "input equals output". This extensible method can create a mixed-reality space within a tabletop environment, in which interaction with virtual objects and real world objects can be integrated seamlessly, bridging the gap between physical world and information world. The proposed method can be applied for, and is capable to bring new interaction experiences to, many different applications from a wide application range such as edutainment and remote collaboration.