First of all, do not let it become stale (sliced bread is particularly moist and tends to produce mold) and use it before.
The most obvious way to recycle sliced bread is to make croutons to add to soup and salads.
Dice the slices, using crumbs and crust, slightly brown them in a pan with a little oil and then add salt (but you can also cook the croutons in a preheated oven at 150 degrees for about ten minutes).
Croutons can also be fried making a double breading; just flour them, pass them in the beaten egg, make a second breading in a mixture of bread crumbs, oregano and grated Parmesan; then fry them in hot seed oil, drain them and dab them with absorbent kitchen paper to remove excess grease.
The croutons made in this way can also be a cheap and tasty snack to serve as an appetizer.
If the slices of bread are still soft, you can fry them with mozzarella or prepare this delicious tart of sliced bread that I found on Cookaround and that you can serve cut into squares as an appetizer or in a picnic.
The stale sliced bread can be also recycled by grating and mixing it with other ingredients for cooking meatballs and meat loafs.
But you can also reuse it soaking it in milk and then use it, squeezed, always in meatballs and to make walnut sauce and other dishes that include the softened stale bread among the ingredients.
Soaked and then squeezed, you can also use it to make desserts, like this genuine cheap chocolate pudding.
If you want to use the grated sliced bread to season pasta (as in the recipe for spaghetti with anchovies), remember to slightly brown it in a pan before adding it to the other ingredients.