The aim of a Room
The only goal of a Room is to store the interface and layout of the program and reuse it.
That means all the position of the panels, if they are opened/closed, the keyboard shortcuts, the color scheme, the Light table parameters, ...
And as there are four Rooms available, it's like you have four TVPaint Animation windows opened at the same time ! It's a Multi Interface Configuration.
Your projects are always the same between each Room, it's only the interface and layout of the panels which change.
If you select another Room with the [Ctrl] + [Alt] keys pressed, the new selected Room will get all the parameters of the previous one. By this way, you can easily copy the layout of a Room into another one.