To change the columns on the candidate list, click the wheel icon and choose Configure datagrid:
A list of fields will be displayed. Click Available fields to see available options:
These are the fields defined by you for the candidate form, so if you want to add new fields to the list, you can do it in Settings -> Candidate form.
Once you make your selection, click Add, and the new column will appear on the candidate list.
To change the column order, drag and drop them on the list. To delete a column, click the x to the right of the field name:
To save selected settings, click the green Save button at the bottom right. Then, refresh the candidate list (press Ctrl + R on the keyboard) to see the changes.