Please, see below how to get column's Total or Average values.

If you want to show such values at the bottom of the table you should enable it in field settings.

Total and Average available for Decimal, Integer and Formula columns.

Open field editing page and click on Total and Averange tab.

The Table total - shows the total for all records in the table.
The Page total - shows the total to a page or group.
The Report total - shows the total for all records in the report.
The Search total - shows the total for search results only.

The Average options work the same way.