In Scandanavian Mythology, Valhalla is the hall where the god Odin recieved the souls of slain heros, so sort of, it is heaven. This comes from Valhöll meaning hall of the slain.
Vahalla(Finnish) is the singular addessive form of 'vaha', where the stem 'vah-' means wax. Although, The stem 'vähä-' means little, which I guess is sort of like half. I guess you could, in theory, pull Vahalla meaning Half-Heaven.