found the answer on this page
Binding-Datatable-to-rdlc-report[
^]
Basically:
1) setup a new dataset with a datatable defined EXACTLY as your table is
2) use mock dataset in the RDLC to bind to table / list / matrix / etc..
3) link the table to the report using
'ReportViewer1.LocalReport.DataSources.Add(New ReportDataSource("DataSet1", reportTable))'
Finished!