Errrrr so why do I get two envelopes of varying thickness per week?
Probably because you opted for the paper version.
The electronic (Jeppview 3) version does have some paper content (the airway charts are still paper) but that turns up only every few months.
You can also choose the CD or download delivery. The CD version costs extra and there is the delay of the CDs being in the mail.
I used to have the Jepp paper sub, just for the UK, and that was bad enough in terms of time wasting, inserting the stuff in. For say Europe, it would take quite a few hours to do all the updates.
Most airlines fly with Jepp plates, and virtually all light jets do.