羊续 is a person
為 in the capacity of
南阳 is a place name
太守 governor
盐豉 salt and fermented beans (for making soya sauce etc)
共 total
一壶 one jug
What it means that this person although is a provincial governor, all he has is a jug of salt and fermented beans to show for, meaning he is an honest and incorruptible official.