Six books I have no connection to showed up in my library after Kobo transfer

I've had my Kobo (bought new from Argos) for a couple of years and decided I wanted to bring some organisation to my library. I downloaded Obok and transferred from my Kobo device to Calibre on my mac. Five books that I not only have never bought, but I've never heard of, turned up in the process? The titles are A Tongue So Sweet and Deadly, Some Desperate Glory, Someone You Can Build A Nest In, The Adventures of Amina Al-sirafi, the Haunting of Tram Car 015, and The Wolf King. I've had my Kobo account a lot longer than the device but these are not in my archive on the site at all and as I say I have no memory of even hearing of the titles before, most of them aren't close to what I would have been reading pre-ereader. There's also a book called Good Spirits that looks familiar but I really don't think I've bought it or even had it from Libby. They all seem to open and to be complete, released books from proper publishing houses. Is this common? Does Calibre come preloaded with books? Do ghost books ever just show up? Brand new to Calibre and google and searching the Reddit didn't seem to yield results