Chapter 42: 7-9
The Laws Pertaining to a Meal7. If two people are eating from the same dish and one pauses in order to drink or perform a minor activity it is proper manners for his colleague also to pause and wait for him. However, if three people are eating from the same dish, and two need not pause for the sake of one.
8. A person may use a loaf of bread for whatever purposes he desires, provided it does not cause the bread to become disgusting. However, it should not be used for a purpose which might cause it to become disgusting. Thus, a loaf cannot be used as a support for a pot containing food, lest the food spill on it.
When one eats a cooked dish and uses a piece of bread as a spoon, one must be careful to eat some of the bread each time and to eat the entire piece when one has concluded.
9. It is forbidden to throw bread, even if doing so will not cause the bread to become disgusting. This is degrading for the bread. Other types of food may not be thrown if dong so will cause them to become disgusting. However, foods that will not become disgusting - e.g., nuts - may be thrown.
A person should not sit on a sack containing fruit, for that causes them to become disgusting. One should not wash one's hands with wine or other beverages, for it is degrading to use food in such a manner.
A person who sees food lying on the ground should pick it up. Food which is fit to be served to people should not be served to animals, for this is using food in a degrading manner.
