I wouldn't recommend to waste time by brute memorisation of stuff that you might never need. Rather skim through the Camel book, so you know where to find something to re-read in case you need it. You could spend more time on the parts that treat structure, concepts, and the non-technical side of perl (e.g. Perl-Culture). Any other interesting stuff will be memorised automatically.

Other Ideas: Higher level concepts can be studied without a computer. Although your computer will not be present, you'll have access to paper? The absence of a computer is a chance to exercise planning and to train conceptual work without being lured into the fiddle along until it works-mode. Maybe you can plan/design your next project and exercise these skills a little bit? Plan the things you'll do (train, program) when you get back to your computer.
E.g., learning some UML can be done nicely w/o a computer if that fits your plans. Patterns and OOP (P: Programming & Perl) are other potential candidates... or reading an SF-novel to recharge the creativity buffers ;-)