» Updating Charts by Dragging and Dropping in Microsoft Excel

If you have a chart with data for 1999 through 2001 and then enter a new column for 2002, you can drag and drop the new data on the chart.
Highlight the cells with the new data E1:E7. Using the mouse, click the black border around the range and begin dragging the range towards the chart. When the mouse pointer is over the chart, release the mouse button.

Result:
the new data is added to the chart. Screenshot // Updating Charts by Dragging and Dropping in Microsoft Excel