Gluttony
He sits at the table and eats so much of the food before him! I would not think that dwarves could eat so much, and yet here Gimli is, stuffing his mouth with so much food it almost overflows. His companions let him feast, as if it could be his last meal. His manners at table are atrocious! Belching, using his hands instead of the utensils offered, and leaving bits of food behind in his beard. And he asks for more food and ale! I begin to thing the dwarf would protect his food as a wildcat protects his kill.
My apologies to the dwarf-lovers out there. This was only me attempting to guess at what Eowyn might've been thinking after meeting Gimil for the first time. Of course, she liked him afterwards... but what about her first impression?