The abstract noun "death" can be expressed with the verb "die." Alternate translation: "until the day he died" (See: [[rc://en/ta/man/jit/figs-abstractnouns]])
The word "household" refers to the people living in the king's palace. Because Azariah was a leper, he had to live in a separate house. So his son, Jotham, took charge over the palace.
Being over the household represents having authority over those in it. Alternate translation: "was in charge of the household" or "had authority over those in Azariah's palace" (See: [[rc://en/ta/man/jit/figs-metaphor]])