I would say that a model should only have the columns necessary for the views that display it, especially if not all views are always visible simultaniously.

Depending on your database you might even be able to make a "view" at the DB side and just display that table with a standard QSql model.

Having data for more than one view accessible through the same model mostly makes sense when these views needs to be easy to synchronize, e.g. highlghting the same row.

Cheers,
_