I know that the question is a bit silly but I dont know how many keys can a MIFARE PLUS tag store in it.
Provided that I have a MIFARE PLUS S tag with 4k memory room and the key length is 128 bit, then the maximum amount of keys stored will be 31. (4000/128 = 31.25 rounded to 31)
It is correct ? The product leaflet doesn't tips how many keys are or if its is more then one.( I am assuming that its so)