Northern French, Vatblé, "meaning obscure", says one expert, but Jean Tosti has some suggestions. If you know some French it's on this page -http://www.jeantosti.com/noms/v2.htm
If not you'll have to make do with the following -
it could mean "spoil wheat" and be a nickname for a miner. The peasantry hated miners, and, it would seem from this that they blamed them for ruining their crops. Another possibility is that it comes from a place name. Tosti lists a couple of place names that could have the same origin though they don't look too similar.