To reproduce: radRichTextEditor.Document = new RadDocument(); radRichTextEditor.Document.MeasureAndArrangeInDefaultSize(); radRichTextEditor.UpdateEditorLayout(); radRichTextEditor.Document.CaretPosition.MoveToLastPositionInDocument(); var p = new Paragraph(); p.Inlines.Add(new Span("Cell")); var cell = new TableCell(); cell.Blocks.Add(p); var row = new TableRow(); row.Cells.Add(cell); var table = new Table(); table.Rows.Add(row); var section = new Section(); section.Blocks.Add(table); radRichTextEditor.Document.Sections.Add(section); radRichTextEditor.Document.CaretPosition.MoveToLastPositionInDocument(); var provider = new RtfFormatProvider(); var txt = provider.Export(radRichTextEditor.Document); Clipboard.SetText(txt, TextDataFormat.Rtf); Workaround: measure the document after the section is added: radRichTextEditor.Document.Sections.Add(section); radRichTextEditor.Document.MeasureAndArrangeInDefaultSize(); radRichTextEditor.UpdateEditorLayout();