Currently, each product can only be added to one category in PowerStore. There has been user feedback to ask for the ability to add a product to multiple categories, so I believe this will be implemented in a future release of Powerstore.
If you are referring to product options, these will need to be added for each product you create. The product options are specific to each product you have. For example, you would create an option of Size, and set the values to Large, Medium and Small.