Certainly a good idea - personally I do something similar but have it in my kneeboard as a couple of extra leaves.
What I keep is:
- UK frequencies card (or equivalent if abroad)
- LARS areas and frequencies
- semicircular and quadrantal rule diagrams (can anybody ever really remember these?)
- Standard emergency squawks
- Morse decode
I also always have a card on there containing all the main numbers for my aeroplane on one side of A5, and another with a generic checklist.
With my PLOG, and a couple of pages from Pooleys typically around 6 A5 cards for everything I should need.
G