Is there a way to create and store an undefined amount of features associated to an item?

Summary:

Is there a way to create and store an undefined amount of features associated to an item without creating flex fields? Our items have defined 'features' but not every item has the same amount of the features and most features are unique to one item instead of applying to multiple. Rather than creating a significant number of flex fields to store these - many of which would contain no data except for the selected item it applies to, is there a way to create custom object that would allow us to add a row and then define a description? Some