I noticed that some random items are listed in my inventory under the section of "account upgrade" why could this be? Some items are food....are they used for something ???

It's been an issue for a long time, there is a thread for items like that here - ⭐ Items in Incorrect Category

Although it says this in the first post:

• Please do not report items in "Special" or "Account Upgrade" categories - staff will work those categories separately.

I'm not sure how frequently it's being looked at right now though since staff is kind of limited, but it is on their radar for something to eventually get to I guess.