There are are a million reasons that someone could check someone’s profile multiple times, for better or worse. The bottom line is who cares? Is it really that important? Come on. I could take my time right now and make a whole list of reasons why someone might do this, both good and maybe not so good but if that person is not bothering you or messaging you too much then just ignore it. If it really bugs you that much then just block them.
Could also be their first day on the site, and they are still learning stuff. Maybe making a list of people that seem interesting in their area, then going back through them again. Maybe they forgot part of your profile. Maybe they have anxiety issues and are working up to sending that first message. I wouldn't read too much into frequent profile visiting unless it's something really absurd.