Cells of type Label. Set cursor to the Label field of the first cell. The field might be gray, indicating that the cell type is not of type Label yet. On this screen, it does not mean inactive. Start typing the label for the cell and the cell type will automatically change to Label. Click on Tab to go down to the next cell label field and repeat. The same technique applies to type Image and Dropdown. You might need to confirm that you really want to change the cell type.

Changing cell types. In the type column, select the cell type from the list by entering the first letter of the cell type. For example for type "Label" click on the "l". The list will jump to the "Label" type. Click on the "Tab" to go to the next cell type field (move down) and repeat.