OK, back to the context. Sam explains to Tyrion that this book is Archmaester Ebrose's "history of the wars following the death of King Robert." Basically it's the collected wiki summaries of Seasons 2 through 8, only written by Jim Broadbent. (Yes, the Oscar winner played Ebrose in the seventh season, if you'll recall.) Sam proudly announces that he helped come up with the title.
Frankly, the onscreen version of A Song of Ice and Fire looks pretty short given how long Martin's books are. Well, that's probably because it, uh, skips all the Tyrion parts. Tyrion's eager to figure out how Ebrose portrayed him, but Sam informs him, "I don't believe you're mentioned."
Tyrion's clearly disappointed, but luckily writers David Benioff and D.B. Weiss thought more highly of him than the fictional archmaester. He ends up not only alive, but in a place of power, having figured out that a solution to everyone's fighting is just to put a creepy, all-seeing dude on the hypothetical Iron Throne. The only thing the showrunners didn't let Tyrion do was finish his joke about bringing a honeycomb and a jackass into a brothel. He starts to tell it before the camera cuts away.
All said, it's almost charming that Game of Thrones managed to have a little fun as it came to a close while paying tribute to the man who started it all. On the other hand, it also debunks a long-running theory that Sam Tarly was a stand-in for George R.R. Martin on the show -- though he still delivered the book, which is perhaps close enough. Now if only Martin could, uh, finish the rest of those books, that'd be sort of nice. It will be interesting to see how he thinks this saga ends.