Displaying QAbstractItemModel in a Table

[jpn]

Is there a way to do this except for writing a completly new view class? Perhaps subclassing QTreeView or QTableView in a smart way?

Try implementing a proxy model. There's an example of a Transpose Proxy Model in our wiki. It doesn't do at all what you want but gives you a simple idea how proxy models are implemented. What you should do is to map the children as top level indices.