What do the following items, " a glass of milk, an apple, and a pear," represent for Montag?

Montg learns and processes a great deal in a short period of time.  He goes from being a follower, a fireman, and part of society's problem, to a rebel, a wanted man, and an intllectual in a very short span of time.  He has gone from being emotionally isolated to emotionally and physically isolated once he is on the run from the firemen and the mechanical hound.

The milk, apple, and pear on the farm represent life's simple pleasures in a tranquil environment.  The items and location represent everything Montag has not had up until that point.  These items represent Montag's desire to rest, contemplate, and just be without having to process or make any more decisions.