Usually 4 tags are supported for most of the cards. If you need more tags to be added while displaying the cards, go to Body-Cards' sheet and 'just add the required tags in column I (Tag4 column) as comma separated values.
For example if you need to display more than 4 tags (apart from what is already used in Tag 1, Tag 2 , Tag 3 and Tag 4 columns), add more tags in Tag 4 column as below with comma separation.
Extra Tag1, Extra Tag2, Extra Tag3
This works only in Tag 4 Column.
If you add comma separated values in other columns - Tag1, Tag2 and Tag3 - the entire tag will be displayed as text with comma.