I'm assuming you use the VR3 as your primary means of knowing what deco you need.
That means then that the written tables are your backup. It would then seem more sensible to have them in a pocket, as you don't need them all the time, only in the "rare" event that a computer fails
As far as working out what numbers to put on, I used to just use a base table for the planned bottom time at the expected depth. Adjustments can then be made on the fly quite easily. As far a a loss of deco gas goes, I generally use a rule of thumb like doubling the stops. Much easier.
Cheers,
Rich