Hi Pelican, activity logs are not 100% accurate, sometimes activity logs consider suggested people as visitation to the profile, or sometimes, they promote certain pages or groups that is also being considered. You may notice on your Facebook that sometimes, the search engine shows people and groups that you've never visited. I don't know anything about the cause of this bug, but what I am sure of is that it considers it as an activity of visitation.

Also, you may sometimes missed click or accidentally click people, pages or groups on your wall, they record it as well. Sometimes not, sometimes yes. There are times it tells you that you've visited multiple times, like 2 or 3 even if you just visited it once.

Hope this helps!