No, 'The Book of Boba Fett doesn't refer to a book,
the show is called The Book of Boba Fett because it is a show that explores the life of the titular character, who used to be a famous bounty hunter but has since left that life to pursue a new one as the head of a family in Jabba’s former territory. In a way, we see Jabba’s life chapter per chapter in this “book.”
Aside from the fact that every episode in The Book of Boba Fett is called a chapter instead of simply an episode, we can also say that this series is a book that tells us the story of Fett in a manner that has been consistent with the previous Star Wars films and the Marvel-published Star Wars comics. Of course, we can also say that this is a book that shows a new chapter in the famed bounty hunter’s life.
That said, this is a show that is more of a book about Boba Fett’s experiences in life and how he finally decided to turn away from his old life as a bounty hunter to establish a family under his own leadership and protection. In a way, he is opening a new chapter in his book.
So no its not exactly a book but just a metaphor for Boba's life
(source for the quoted paragraphs).