I've still got a bulky desktop scanner that I occasionally break out. Most of the time it does nothing, and it takes up one of only three drawers I have in my desk, which is not ideal.
A good alternative might be this DO-CAM document camera by manufacturer Ipevo, which folds flat, down to the size of a pencil case.
I'm digging the designey-from-the-'90s aesthetic; this looks like it would've been featured in I.D. or Metropolis magazine.
They also make these still-small, but non-portable V4K variants:
And they offer this wireless VZ-X version, which has a battery life of 9-12 hours. The design is not as elegant, but it does have a small footprint and could live on the desk. I think for occasional use it would still be more convenient than pulling out the scanner.
The thing I'm wondering is: Why hasn't anyone combined one of these with a desk lamp? If it's going to live on your desk anyway, it might as well do double-duty, and the components all seem small enough that they'd both fit into a single object.