We can notice that, when more than 6 fields are placed in columns or rows, by default, the first two fields are concatenated by a comma.

(in the above picture, fields ‘Region’ and ‘Country’ got concatenated)

To avoid this, select Analysis > Table Layout > Advanced

A new window “Table Options” appears. On the new window, increase the maximum number of rows or columns as desired.

Note that Tableau restricts the maximum rows or columns to 16.