Staircases take up a lot of space, so why not use them for storage as well. Imagine each step is a box with a hidden drawer in it still allowing for additional storage or home office space beneath the staircase.
The table is like a solid cube. Until it opens It has a flat service when it is closed or not, which is a characteristic of a table. Either way it is a table. it could be a side table when it looks like a cube or dinner for two when you pull it apart.
A space for your secrets. The latest project by Japanese studio Torafu Architects may look like a standard floating shelf, but it actually contains a slim secret drawer that can be opened with magnets.