Foreshadowing in The Canterbury Tales
"Pilate" is an allusion to Pontius Pilate, the man who orders Jesus's crucifixion. The Miller interrupts the Monk, who is comes next in the social order, so that he can tell his story. His failure to remove his hat demonstrates his disrespect for the other pilgrims and the tavern, while his "Pilate" voice suggests that this character is blasphemous. This introduction to the Miller's tale foreshadows the inappropriate and crude tale that will follow.
The burning of this book is symbolic for the end of her husband's authority. The Wife and her husband have switched roles: she now governs the lands while he dotes upon her. Alison's personal story foreshadows the story that she will tell the pilgrims. However, notice that in her personal story, she need to both use and endure violence in order to gain her authority, while the character in the story does not.
Notice how quickly the rioters forget their vow to kill death in the presence of money. Their willingness to abandon their noble (if not foolish) quest demonstrates the weakness of their moral characters. This foreshadows their downfall and the Pardoner's ultimate theme that greed is the most dangerous vice of men.