My theory is that #Roman_Dodecahedrons are combination stands and hand-holders for the #Roman equivalent of Rushlights.
The multifaceted design means you can always find the hole at the top for your unlit rushlight even in pitch black; and it is easy to manipulate the stalk of the rushlight into a corner at the base.
The bobbles stop it slipping out of your hands, and potentially keep your hand away from the face nearest the expose flame.
