block.cs

private Table AddMergeBlock(string tableName, DataSourceManager dataSourceManager)
{
  // get the columns of the data table
  var columns = dataSourceManager.DataTables[tableName].Columns;

  // list of column names
  var columnNames = columns.Select(c => c.ColumnName).ToList();

  // create a new merge block info
  MergeBlockInfo mergeBlockInfo = new MergeBlockInfo(tableName)
  {
    ColumnNames = columnNames
  };

  // create a new merge block settings
  MergeBlockSettings mergeBlockSettings = new MergeBlockSettings()
  {
    BlockTemplateType = BlockTemplateType.TableRow,
    CreateHeaderRow = true
  };

  // insert the merge block
  dataSourceManager.InsertMergeBlock(textControl1, mergeBlockInfo, mergeBlockSettings);

  return mergeBlockSettings.CreatedTable;
}