A quick search hasn't turned up any floorplans online, so I can't point to any specifics. That said, Cabaret was originally a combination restaurant/stage. I did have the opportunity to visit a French Cabaret a couple years ago, and while they prohibited photography inside, I recall that the basic floorplan was a large T-shaped stage, flanked by long tables. The perimeter of the room was elevated and featured more tables, although shorter (mostly 6 or 8 people, with the main floor seating 3-4 times that number). There was a balcony, although I did not get the opportunity to see what the seating arrangements were.
To provide some additional scale, the stage was large enough to support a swinging trapeze act - if there was a platform there was only a single one, at the back of the stage.