Thanks to each one of you for the great info. I understood that you can store you mined coins in a single wallet as long as they are supported from it. Also when you mine that coin you need to enter the specific coin address to the miner (you get the address from the multi-wallet).

Also you can get the original wallet from the coin you mine, so you have one wallet for each different coin you mine (more secure).

I'm mining coins that are from 0,5-10$ value!!!