Hey! It's a really hard book to read for someone who's studying the language.. because it's not in modern italian and it has lots of particoular words. Also, the author uses lots of metaphors and stuff like that so if it's not your first language it's pretty hard to understand (but even if it's your first.. we study the book at school so teachers can explain it to us!). When he says "Mangiatemi pure cogli occhi, che briciole non ne faremo" he means that if they eat him all (metaphorically of course) there won't be anything left.. not even bread crumbs. In italian briciole is not only about bread, it's all the little parts of food that you leave on the table after you eat.
Fascio means bundle. I'll put it in a sentence so you can understand: Una contadina ha riunito delle spighe di grano in un fascio. A farmer fitted some sheaf of weath in a bundle.
I hope my explanation is clear, if you want to improve your italian get on my profile and book a lesson!