Here is an old trick from Chart/Data Table Total Row
Step 1: create a chart including the totals:
Step 2: select the Total series.
On the Format tab of the ribbon, under Chart Tools, click 'Format Selection'.
a) Under Series Options, plot the series on the Secondary Axis:
b) Under Fill & line, set the series to use No Fill and No Line:
The Total series is now completely invisible, but still shown in the Data Table: