Hi Justin,
Are you trying to generate a report of the entire table or specific records? If its for the entire table, then in your template, don't specify an input object (leave it blank), and when you call the Generate excel doc java action set input object to empty. This will export an excel doc of all the records in the table that you specified in your template.
If you want to generate a report with specific records, you can use the input object field on the template, and then in your worksheet template, use the "Reference to template input object" to constrain your data by an association.