I figured it wasn't the text of journal entry, I was hoping to find an Easter egg in it though. But you're probably right about it being some unrelated Greek text. It looks hand written with modern lettering (as opposed to the all caps used anciently), so I was holding out hope the devs had written something themselves like they did for the inscription on Asterion's horns. That being said I have no idea how much Greek language knowledge the devs actually have, and a document that long would require quite a lot.