Can I make baked veal more soft?
Depending on how far overcooked it is, then you might be able to resuscitate it by cutting it into smaller pieces and cooking it low and slow in some liquid.

For example, you could use it as the meat in a stew, or slice it thinly and then braise it with some vegetable to make a pot-roast.

This also gives you an opportunity to introduce additional flavor, as it sounds as if that may have been lacking as well.