Since they live and eat here, they must have a food storage somewhere. Most likely, it's in the largest tent, the goblin figured. And since he's not allowed in, it means they don't want to share. So, he decided to go around it and sneak in through some hole or crawl under the canvas.
Geb was waiting for Amy and the goblin to return.
***
The orc who remained (as I understand) near the palace could see a young elf running away from several men and two women with various household items: pitchforks, brooms, and the like.