I have looked high and low for such a thing, but nothing turned up.
In my experience it’s a bit of trial-and-error. You could try creating a pivot table that pulls in all tables. It’s kludgy (and whatever you do, don’t refresh lest you break the network) but it should give you a high level view.
As for a list of possible GUID relationships, that also eludes me. But I’ve gotten by fine so far using any fields that have “ID” in the name.