Yes, you are free to set up as many stores as you want, though we don’t see any need for that since you could rather differentiate the goods with appropriate categories. The more you have products in your store the more buyers you attract in the Mall. So, creating a lot of single stores doesn’t really help to make your products more visible.
Note that one account can accommodate just one shop. So, for creating more stores you need to register more user accounts as well.