I'm pretty sure I win the prize for "Smallest Workshop," at least when I'm at work.
I work in the oilfied, and live in my 5th wheel for 20-60 days at a time. I got tired of not being able to work on projects while deployed, so I currently use my pretty much useless-to-me couch inside my living room slideout as a base for my workbench.
My chair is my igloo cooler:
Tools:
I do have enough room that I recently added a balsa dust filtration system

lol... :
Here's the exterior of my workshop:
And the view out the window over my workbench: