Light court Worktable
Although there were many variations of furniture configurations in the atrium light court over the buildings lifespan, the original design consisted of two desk arrangements. One long desk with lights at each end, and a second that was slightly smaller without lights. These can be seen in the black and white image below. This group of images demonstrates the design of the larger of the two.
This desk group utilized the three-legged office chair, also known as the “suicide chair” because it was so unstable, and the folding pedestal chair that was exceptionally heavy and uncomfortable. [i] 
Large Atrium Work Table
Historic Context
In this photo the large desk is shown with the smaller desk appearing in every other row. This configuration can also be seen in the plan below.
The light court of the Larkin Administration building.
[i] Jack Quinan, Frank Lloyd Wright’s Larkin Building-Myth and Fact, The Architectural History Foundation (New York, New York 1987) p.62