TableColumn

var tableDef = new Telerik.Reporting.Table();

tableDef.ItemDataBound += delegate(object sender, EventArgs args)
{
    Telerik.Reporting.Processing.Table table = (Telerik.Reporting.Processing.Table)sender;

    foreach (Telerik.Reporting.Processing.TableColumn column in table.Columns)
    {
        for (int rowIndex = 0; rowIndex < table.Rows.Count; rowIndex++)
        {
            Telerik.Reporting.Processing.ITableCell cell = column.GetCell(rowIndex);

            if (cell.RowIndex == rowIndex
                && cell.ColumnIndex == column.Index)
            {
                Telerik.Reporting.Processing.ReportItem item = cell.Item;

                // Here you can do something with the report item
            }
            else
            {
                // Do nothing. This is part of a merged table cell.
            }
        }
    }
};

Private Sub TableDef_ItemDataBound2(ByVal sender As Object, ByVal e As EventArgs) Handles tableDef.ItemDataBound
    Dim table As Telerik.Reporting.Processing.Table = DirectCast(sender, Telerik.Reporting.Processing.Table)

    For Each column As Telerik.Reporting.Processing.TableColumn In table.Columns
        For rowIndex As Integer = 0 To table.Rows.Count - 1
            Dim cell As Telerik.Reporting.Processing.ITableCell = column.GetCell(rowIndex)

            If cell.RowIndex = rowIndex AndAlso cell.ColumnIndex = column.Index Then
                Dim item As Telerik.Reporting.Processing.ReportItem = cell.Item

                ' Here you can do something with the report item

            Else

                ' Do nothing. This is part of a merged table cell

            End If
        Next
    Next
End Sub