Answer:
He feels disgusted by the wasteful nature of war.
Step-by-step explanation:
Grendel states that he is confused and disgusted by why so many animals and humans are killed without any purpose. Grendel is self-portrayed as the monster, but his killings are for food, with a purpose.
He describes the horror of war with disgust. Grendel then stated that, in war, people kill without any function and for any reason that they can think of; animals and humans are left to rot or burn, which he finds very wasteful in nature.