Swiss Cheese Slices can be frozen if you want to freeze them and freezing the Swiss Cheese Slices will help extend the life of the cheese and keep it from going bad sooner like it would in the refrigerator.
Although freezing cheese can change the texture and taste of the cheese including Swiss Cheese Slices but other than that it's perfectly fine to freeze the Swiss Cheese Slices.
Then when you want to eat them or use the Swiss Cheese Slices for Cooking you can sit them out at room temperature for 30 minutes to an hour prior to eating them or using them for cooking.
You can keep Swiss Cheese Slices in the freezer safely for up to a year or more although the freshness won't be there after 6 months but it's still safe to eat the cheese.