'create report instance
Dim report As New MyReport()
'set the report's data source
report.DataSource = GetReportData()
'get the nested data item and set its DataSource
Dim nestedDataItem = DirectCast(report.Items.Find("table1",True)(0), Telerik.Reporting.Table)
nestedDataItem.DataSource = GetTableData()
'display the report
Dim IRS As New Telerik.Reporting.InstanceReportSource()
IRS.ReportDocument = report
'send parameters' values if needed
'the ReportSource.Parameters collection is mapped by key to the report's ReportParameters collection
IRS.Parameters.Add("Parameter1",newvalue)
reportViewer1.ReportSource = IRS