The most common and most likely answer to this crossword clue is the 8 letter word PAGINATE
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More clues leading to the result PAGINATE
Buddy explains!

The straight part
We know that "Number the entire book" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case number the entire book = paginate.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PAGINATE mean?
PAGINATE verb- To number the pages of (a book or other document); to foliate.
- To separate (data) into batches, so that it can be retrieved with a number of smaller requests.