Decreasing Performance of Table Creation in Content Controls in Word 2010

Reproduction.cs

private void OnButtonCreateTablesClick(object sender, EventArgs e)
{
	var document = Globals.ThisDocument.InnerObject;
	var stopwatch = Stopwatch.StartNew();

	try
	{
		document.Application.ScreenUpdating = false;

		for (var id = 1; id <= 10; id++)
		{
			CreateTable(document, id);
		}
	}
	catch (Exception exception)
	{
		MessageBox.Show(exception.Message);
	}
	finally
	{
		document.Application.ScreenUpdating = true;
		if (checkBoxClearUndo.Checked) document.UndoClear();
	}

	stopwatch.Stop();
	var memorySize = Process.GetCurrentProcess().PrivateMemorySize64 / 1024.0 / 1024.0;

	listBoxTimes.Items.Add(String.Format("{0:00.000} s\t{1:0.000} MB", stopwatch.Elapsed.TotalSeconds, memorySize));
	listBoxTimes.SelectedIndex = listBoxTimes.Items.Count - 1;
}

private object _oEndOfDoc = "\\endofdoc";

private void CreateTable(Document document, int id)
{
	ContentControl contentControl;
	if (document.ContentControls.Count >= id)
	{
		contentControl = document.ContentControls[id];
	}
	else
	{
		var range = document.Bookmarks.get_Item(ref _oEndOfDoc).Range;
		range.Paragraphs.Add();
		range = document.Bookmarks.get_Item(ref _oEndOfDoc).Range;

		contentControl = document.ContentControls.Add(WdContentControlType.wdContentControlRichText, range);
		contentControl.SetPlaceholderText(Text: "Table " + id);
	}

	var data = "";
	var style = 0;

	var table = document.Tables.Add(contentControl.Range, 30, 15);
	for (var row = 1; row <= table.Rows.Count; row++)
	{
		for (var column = 1; column <= table.Columns.Count; column++)
		{
			data += String.Format("Table {0}, Cell {1}|{2}", id, row, column);
			if (column != table.Columns.Count) data += "\t";
		}

		if (row != table.Rows.Count) data += Environment.NewLine;
	}

	Clipboard.SetText(data);
	table.Range.Paste();

	for (var row = 1; row <= table.Rows.Count; row++)
	{
		object styleName = String.Format("MyStyle{0}", (style++) + 1);
		table.Rows[row].Range.set_Style(ref styleName);

		style = style % 3;
	}

	var cellRange = table.Cell(1, 1).Range;
	var innerTable = cellRange.Tables.Add(cellRange, 3, 3);
	innerTable.Cell(1, 1).Range.Text = "123";
	innerTable.Cell(1, 2).Range.Text = "456";
	innerTable.Cell(1, 3).Range.Text = "789";

	cellRange = table.Cell(1, 2).Range;
	innerTable = cellRange.Tables.Add(cellRange, 3, 3);
	innerTable.Cell(1, 1).Range.Text = "123";
	innerTable.Cell(1, 2).Range.Text = "456";
	innerTable.Cell(1, 3).Range.Text = "789";

	cellRange = table.Cell(1, 3).Range;
	innerTable = cellRange.Tables.Add(cellRange, 3, 3);
	innerTable.Cell(1, 1).Range.Text = "123";
	innerTable.Cell(1, 2).Range.Text = "456";
	innerTable.Cell(1, 3).Range.Text = "789";
}

private void OnButtonClearTablesClick(object sender, EventArgs e)
{
	var document = Globals.ThisDocument.InnerObject;
	try
	{
		Globals.ThisDocument.Application.ScreenUpdating = false;

		foreach (ContentControl contentControl in document.ContentControls)
		{
			foreach (Table existingTable in contentControl.Range.Tables)
			{
				existingTable.Delete();
			}

			contentControl.Range.Text = "";
			contentControl.Range.set_Style(WdBuiltinStyle.wdStyleNormal);
		}
	}
	finally
	{
		Globals.ThisDocument.Application.ScreenUpdating = true;
	}
}