book up

verb4

1. •
   To reserve or book all of something, for example by purchasing all the tickets.
2. •
   To have all of its tickets or reservations purchased.

   • Flights are beginning to book up as people flee the region.
3. •
   (slang) To study opening lines in great detail in order to gain an advantage.
4. •
   (slang) To study or learn (something).