The Word Shaker was a book written by max for Liesel. It is an allegory to what was happening in Germany at the time and plays an important role later in the book, during part ten (the book thief) way of the words.
What Is The Word Shaker In The Book Thief?
The ones who knew the true power of words were best word shakers
The Word Shaker is the book Max made for liesel before he left there house.