The Table of Comets: Galaxy Quadrant YX-12-114 was a reference book used aboard the USS Enterprise.
A copy of the book was in the briefing room during the Neutral Zone Incursion. James T. Kirk wanted to refer to the book to learn more about the composition of the comet Icarus IV. Spock, however, held the book back stating that the the comet was "quite ordinary," and continued to explain the comet's composition without requiring its reference. (TOS: "Balance of Terror")