I noticed that I received some kind of airdrops on a Polygon address, although I'm not sure when I applied. It doesn't matter.
Can someone specifically explain what the purpose of these tokens is and why someone does this at all?
I have no intention of dealing with that token, but I see that it was sent to many addresses, I believe that someone will think that they can get something out of there.
The address from which it was sent is labelled as Fake_Phishing3312

If it's a type of scam, how is it realized?
Yes, this is scam token and I must inform you that such kind of scam tokens are common, I have been receiving them on numerous times.
Honestly, if you did not apply for such project airdrops, ICO/IDO, there is no point trying to send or use them any way. It is a trap!
Many scammers believe that if they send free coins to numerous people, there may be some that will fall for the trap. Indeed it is a trap especially for those that are newbie or covetous crypto enthusiast. scammers feel some victims will get this free tokens not knowing what is underneath.
Now, some of these free sent tokens are strategic ways scammers track your wallet informations, it is not advisable to swap, send or even ask for information on how to used them.