Hi,
I think you should create a new local small web and put the html script in.
And I've found a example create by Jeremy Likness and I think it is fantastic:
http://csharperimage.jeremylikness.com/2010/09/hosting-html-in-silverlight-not-out-of.html
After reading the article,just use
<Grid x:Name="LayoutRoot">
<HtmlExample:HtmlHost x:Name="HtmlHostCtrl" Margin="40" HorizontalAlignment="Stretch" Height="400" Width="600" VerticalAlignment="Stretch" HostDiv="htmlHost" Url="http://m.google.com/"/>
</Grid>
You can see the page in the silverlight page!