Why does this Flow Document take up more space than it needs?

Question

The height of the object is about 60 pixels, but the text is only about 12 pixels tall. I tried setting the Height="30" but then the text wasn't readable.

<RichTextBox IsReadOnly="True" Focusable="False" >
    <FlowDocument xml:space="preserve" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" >
        <Table>
            <TableRowGroup>
                <TableRow>
                    <TableCell BorderThickness="0" >
                        <Paragraph>
                            <Bold>
                                <Run Text="test"/>
                            </Bold>
                        </Paragraph>
                    </TableCell>
                </TableRow>
            </TableRowGroup>
        </Table>
    </FlowDocument>
</RichTextBox>

Answer 1

Using a paragraph gives you an extra line at the top and the bottom. In code you can do this

Paragraph p = this.rtbCommandLine.Document.Blocks.FirstBlock as Paragraph; 
p.LineHeight = 10;

And programmatically add your Runs... I don't know how to do it in XAML