A 700 non-fiction book could be  written about

Architecture, Crafts, Drawing, Games, Jokes, Music, Puppets, Songbooks, or Sports.

 The 700's are located to the left of the storage room door in the tall shelving against the wall. 

They are filed numerically according to their Dewey Decimal subject and

hen alphabetically by the first 3 letters of the author's last name.

Dewey wanted to pull some of the books and check them out.

Huey and Louie pulled him away to the 800 section.