The merchant sure is a handy exposition dump. So Laen had all those status effects constantly reducing her abilities and halving her effective level, it's no wonder she can't defeat simple goblins. But when did she get poisoned? If it was before Ragna arrived, how has her home not been ransacked already? How come she didn't tell Ragna she was expecting a guest (the merchant) to arrive that day? Ragna really is damned stupid though, he can't deduce anything. And what a weird way to wash dishes; the surface of the side of a blade typically isn't completely flat, so it won't provide as a very stable resting spot for plates or cups.