I know that this thread is three months old and that no one has yet replied but I am shamelessly resurrecting it as I would like to ask the same question and it seems silly to start a new thread on the same subject.
I too would like to edit custom field contents without having to edit each individual gallery item, save, find the next one, edit, save ad nauseum.
I have many hundreds to edit and a more direct route to the database would be good.
