The dictionary says the meaning is ‘there it is’ or ‘there you are’. Looks like use it when fixing problems? Like, you need to sew on a button but don’t have a needle. You rummage around in a drawer, find a needle and say ‘voila!’. Like I tend to say ‘ta da’!. Which sounds like a simplified version of voila, now that I think about it.
Makes sense, I’ll try using it around the house. Or when shopping