Multiple realities(covers information from several alternate timelines)
Traditionally, a notebook was a book consisting of several sheets of paper bound together. A PADD and its contents could also be considered a notebook. (DS9: "The Emperor's New Cloak")
In 2258 of the alternate reality, Montgomery Scott's workstation on Delta Vega had a spiral-bound notebook resting on it. (Star Trek)
Leonardo da Vinci was to publish his notebooks, but never got around to it. In 2374, "Catarina" questioned a hologram of Leonardo da Vinci as to why that was. (VOY: "Concerning Flight")
Sections of these notebooks made it into the Enterprise opening credits.