2 attack=the attack bonus which means better chance of hitting, only the sword of quickness and a few other weapons have multiple attacks (such as gloves of the gladiator)
The CB mod made some changes to up the number of attacks of some otherwise underwhelming weapons... the Fire Bola is my current favorite: Equip one of those and the Sandals of the Crane to a giant or banelord for a really irritating thug!