EjectedMisuse of a fetch modus (such as accidentally activating a hashtable may cause items to "fall out" of your inventory. They will be dropped in a random direction, and they can go several blocks. They may fall off a cliff, so watch out.
If there is a nearby mob, items may be launched at the mob, causing damage and possibly killing it. Mobs can be damaged through blocks even though items can't go through blocks.