When the party first travels there, he gives the companions advice on crossing the swamp, where the Midgar Zolom lurks, as Sephiroth was allegedly headed in that direction. He also offers a bed for the night. Later in the game he also rents them stables for 10,000 gil each allowing them to start breeding Chocobos.
食う / くう / kuu is a rough way to say "eat", whose volitional casual form is 食え / くえ / kue ("let's scoff 'em down!"), leading to Kweh!