You can add a row total for any numeric column in a table chart. Additionally, you can customize the aggregation type used for each column.
From within the Data Explorer, click the Chart Settings button.
Check the Show row aggregation for numeric columns checkbox. Click Done when finished.
The total row will always display at the bottom of the chart, even if all of the rows don't fit in the available chart space.
Set custom aggregations for each column
The aggregation row defaults to sum for each numeric column. However, you can change the aggregation per column as needed.
To change the aggregation type, open the Chart Settings and switch to the Columns tab. Click the Add New Formatting Rule button. Select your column from the dropdown, and adjust the Aggregate Row setting to choose a custom aggregation.