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.
There's a slightly larger version in the Big folder but it's still pretty unreadable. 
Thanks for finding this. I looked at it and thought I might be able to transcribe it to make it more readable, but there are enough letters that I can't make out to even transcribe it.
Its frustrating because I can make out a number of words that are part of my limited Greek vocabulary that I can tell that it's not just nonsense, but then I can't even make out all the letters in the second word.
Attempting to read this feels rather like the description of trying to read it in game. My brain feels like I can almost latch on to it and make it fit together but then it slips and losses track of what I thought I saw.
I'm dyslexic, and looking at this reminds me of what reading felt like when I was still training myself to make sense of words.
