Mid Summer Tavern Brawl Has Infinitely respawning bread on the tables - Use it!
You Must Throw the Bread, It Must Kill the person, Not knock him down.
If that game mode is not available the map with "Defend the Hamlet" Objective has bread on the hamlet tables, and Lionspire has bread on various tables as well, but the chance of a player "Going down" instead of dying from the bread throw is higher in these maps.
Goodluck!