(written from a Production point of view)
Star Trek: The Captain's Table was a series of thematic crossover novels released by Pocket Books. The books spanned all four major Trek television tie-in novel series (at that time), including TOS, TNG, DS9 and Voyager, additional installments featured stories based on Star Trek: New Frontier and an adventure of Christopher Pike based on "The Cage".
In 2005, Pocket Books revisited the Captain's Table with an anthology Tales from the Captain's Table, featuring the captains who'd been added to the Trek pantheon in the years since the original miniseries: Jonathan Archer (Enterprise), William T. Riker (Titan), Kira Nerys (Deep Space Nine), Chakotay (Voyager), Elizabeth Shelby (Star Trek: New Frontier), David Gold (Star Trek: SCE), Klag, son of M'Raq (Star Trek: IKS Gorkon), and Demora Sulu (Star Trek: The Lost Era), plus a story of Jean-Luc Picard and the Stargazer.
The Captain's Table is a mysterious bar, run by a being known only as "Cap". Only captains (or people who were at a time acting captains) are entitled to enter the establishment. Traditionally, new captains are brought to the bar by their friends or former commanding officers; Captain Picard introduced Captain Riker upon his promotion.
The bar appears to exist in another dimension because its door can appear anywhere around the galaxy, and it is visible only to captains. This is corroborated by the fact that the bar door could not be seen by Tom Paris when he was on an away mission with Captain Janeway; it appeared to the young M'k'n'zy on the planet Xenex, and even to Captain E.J. Smith of the RMS Titanic while aboard his vessel.
Drinks in the bar are provided free of any monetary charge; the "payment" required by the proprietor is for the captain to tell a story to the rest of the patrons. This story does not necessarily have to be about the captain, nor does it have to be true; Captain Archer entertained the bar with a suspense-filled (and, from the perspective of the reader, plainly false) tale of his first meeting with "Porthos the Great", portraying the beagle as a famous spy-dog.
Thus, the Captain's Table novels are a collection of short stories, each told by a captain or commander from Trek lore, bookended by short sequences taking place inside the Captain's Table bar.
The author of each book can be seen as a background character in the cover art.