A table for a room with no floor
On Earth a table is a flat plane because gravity holds things on it. In orbit it holds nothing, and every assumption behind its shape disappears.
The flat table is a gravity artefact
A table is a horizontal plane at the height of a seated person, because gravity presses objects onto it and because our legs fold the way they do. Remove gravity and nothing about that survives. Objects do not rest. Nobody sits. There is no up to orient the surface against.
Stations still fly flat tables. The crew gathers at one for meals and for the photographs that go home, which is the clearest sign that the table is doing social work even when it is doing no physical work.
A sphere instead of a plane
If the point of a table is that people face each other and share what is between them, the honest shape in microgravity is a sphere rather than a disc. A spherical table has no top and no underside. Every crew member approaches it from their own orientation and still sees the same center and the same faces.
The surface is a restraint rather than a shelf: a soft shell with anchor points and shallow recesses, where a pouch, a tool or a cup is docked rather than placed. Nothing drifts away, and nothing has to be caught.
What it has to do
Why it matters
Furniture is where a habitat stops being a vehicle and starts being a place. A table that works in microgravity gives a crew somewhere to be together without fighting the environment, which is the same argument we make about sleep, waste and light: the ordinary parts of the day are where habitability is won or lost.
The concept is unbuilt. It belongs with the Martian chair and the sleeping device as part of a longer study of what furniture becomes when gravity is no longer doing the work.