"Los Libros Del Saber" (The Books of Knowledge) seems to be a series of books related to Elden Ring, possibly a companion to the game or a source of lore and background information.

The "Volumen I" you're referring to likely indicates that this is the first book in the series. Unfortunately, I couldn't find much information on the specific contents of this book.

As for a PDF version, I couldn't confirm whether an official or unofficial PDF of "Elden Ring Los Libros Del Saber Volumen I" exists. Be cautious when searching for PDFs, as they might be unofficial leaks or scans, which could be subject to copyright issues.

Elden Ring is an upcoming action role-playing game developed by FromSoftware, the creators of the Dark Souls series and Sekiro: Shadows Die Twice. The game is set in a dark fantasy world and promises to offer a vast open world to explore, challenging gameplay, and a rich lore.

Would you like to know more about Elden Ring or is there something else I can help you with?