Looks like what casinos do when they throw cards away so they can't be scavenged and used for play.
The police explicitly commented that you play with those circular cutouts and confirmed it again after confused questions by users but that could be wrong of course.
Ah. I didn't pick that up from the Google translated version I read.
The game is likely Xoc Dia, a common gambling game played with four tokens hidden under a bowl.
i would guess it makes the deck unique so cards can't be added on the fly