The data table is used by the Custom Chart. There are five picklists that allow you to customize the data to be displayed in a table of values, bar chart or line graph.
Apply Preset - This button contains a list of presets to get you started on using the custom chart. The presets include code to access current node values, table values, bundle values, and getting object input/output values.
See the Custom Chart page for more information on the picklists.