bind one report with datasat has multipe datatables

I have one Dataset (XSD) with one big data table (represent 2 tables)
I bind this dataset with ReportViewer like this:

        reportViewer1.ProcessingMode = ProcessingMode.Local;
         reportViewer1.LocalReport.ReportPath = 
 

"Master_re_Details.rdlc";

       reportViewer1.LocalReport.DataSources.Add(new 
 

ReportDataSource("DataSet1", this.B_ds.Tables[1]));
reportViewer1.RefreshReport();

        reportViewer1.LocalReport.DataSources.Add(new 
 

ReportDataSource("DataSet1", this.B_ds.Tables[0]));

        reportViewer1.RefreshReport();
 

but i get the value from only one datasource only Tables[1] or Tables

[0] but not both of them!
(I guess the first one used)
where is the mistake??

---