Semi-portable macroscopic devices into which information and stories were typically inscribed by means of inks printed into "paper". Primarily made from trees and various plants and fibers, and commonly found glossed and polished on the outside or wrapped in cowhides.
P-books were considerably weighty depending on the amount of information stored inside them, and despite their size USUALLY CONTAINED ONLY ONE TITLE!!
Full sets of Encyclopaedia inscribed in p-book format often WEIGHED MORE THAN A HUMAN BEING!!
"Libraries" of the time were ENTIRE BUILDINGS DEVOTED TO LESS THAN ONE EXABYTE of information!!!
You will never know the joys of owning over a thousand p-books until you move them down six flights of stairs and back up three more. Makes you wonder how people lived through their University days back then without constant chiropractic care..