I was looking in my chrome settings for something and saw that a discourse forum I am in was storing 2 cookies which comprised 1.2GB of data! I had only logged into it yesterday for the first time on this laptop. Thinking it might be some weird anomaly, I deleted the cookies and then logged back into the forum. I checked the cookies again and the data size was 5.3 MB (already way too big just for logging in). Then I clicked around on a few threads and checked the size again and it was 919MB. I am using the latest version of chrome on a chromebook.
I guess you are talking about
This are not cookies, as but a misreported number in the “Cache storage”.