If you need to add new "Product family" category - try to open List settings(gear in the upper right corner -> List settings) then click on column named "Product family" in columns section and look what the type of the column.
If type is Choice
- Click on this column and add new category
If type is Lookup
- Click on this column and look what is the name of lookup list
- Click on Site contents(gear in the upper right corner -> Site contents)
- Open lookup list
- Add new item in this list
If type is Single line of text
- Just add new item in your list and fill new category in the field "Product family"