That's correct. Keep in mind, though, that this is not the actual damage that's done, as other bonuses (blessings, skills, str bonus, etc) will be applied on top of the base weapon damage. Also, as Coelocanth touched on, the level of enchantment of a weapon affects more than just the extra bit of damage it adds. Many monsters, particularly later in the game, have damage resistance that will negate most (or often all) of the damage of a weapon unless the weapon has a certain level of enchantment (e.g. +1, +2, +3, etc). Generally you want to try to make sure your melee characters are using weapons with as high a level of enchantment as you can get to ensure you don't run into a situation where you can't even scratch a tough enemy. Some weapons will also come with elemental damage, which will usually be along the lines of, say, +1D6 fire damage, which can be nice to have as in addition to the extra damage elemental damage is subject to different resistances than straight up physical damage types (for instance, skeletons have resistance to piercing and slashing damage, so a warrior with a sword will have a tough time doing much damage to them, but if that sword has some bonus fire damage that damage won't be reduced at all, since skeletons have no resistance to fire).