The books of Prospero in this play are a very interesting symbol, because at once they stand for both the incredible magical power that Prospero has gained through his magic arts but also his isolation from human society, that in a sense, becomes a kind of weakness in itself. Caliban clearly indicates the way that Prospero's books are responsible for his tremendous power and authority on the island with his plan to steal them and therefore take away that power:

Remember
First to possess his books, for without them,
He's but a sot.

However, the play makes it clear that, ironically, it was Prospero's intense study of these books that made it possible for his brother to seize power and exile him. The books therefore stand too for Prospero's willingness to remove himself from the world. At the end of the play, Prospero realises that to re-enter the world that he has been exiled from he will need to burn his books and give up his magical powers. Note what he promises to do in Act V scene 1:

For I'll break my staff,
Bury it certain fathoms in the earth,
And deeper than did every plummet sound
I'll drown my book.

The books of Prospero therefore are powerful symbols both of Prospero's magical abilities and authority but also of isolation and withdrawing from the world of men.