They are standard magic card sleeve sized. Not sure about the gold cards, they are minis.
But no, the tray was not constructed with this in mind.
On the plus side, the kind of handling these cards get is not likely to damage them overly. No need to shuffle them.
I beg to differ. The nervous handling of cards and players moving and shuffling their cards has happened in a lot of the games I have played in.
But it is nice that they are MTG sized, which makes finding sleeves easy.