COVID 19 week 3 and so much to do. Where to start? Gotta get organised - write a list! Where - desks & tables already occupied. Need a writing/typing space that goes anywhere - notebook/blackboard/whiteboard?
Solution - notebook on tiny standing desk that packs away when I don't need it...

Supplies

Desktop - mine is repurposed ply, 750mm X 340mm and 16mm thick.
4 X 12mm cup hooks
Shock cord or strong elastic (or 4 hair ties)

Step 1: Install Cup Hooks

Mark the location for the cup hooks - you need to ensure you will have room to hook the loops of the shock cord or elastic into place once assembled.
Screw cup hooks into place.
I made my worktop to fit an art cupboard I have set up for grandchildren, so I installed the cup hooks to fit with 5mm allowance each side.
You could use this workspace between two kitchen chairs just as well by modifying this configuration of the elastic (see photo on next step).

Step 2: Secure With Elastic or Shock Cord

Cut shock cord or elastic to size with an allowance and make a small loop in each end.
Make sure it is short enough to provide some tension.
You might even consider more than one set or pair for different locations (see photos) - I'm using hair elastic to attach it to my kitchen chairs.

Step 3: Get to Work

Now you have a workspace that you can assemble and disassemble in less than 10 seconds and yet is secure enough for your laptop and a coffee!
Add a cabinet on wheels and you have a portable mini office.