Items listed in the Data panel on the right of the report can be dragged and dropped onto the report to create new columns. Note that this requires careful placement of the cells. Drop the cell on the edge of the column it will appear next to. A narrow orange box will appear to indicate it’s time to drop. A column should then appear in the table. If you make a mistake, click the undo arrow in the tools.

Select the column you wish to delete, right-click, and select "Delete"