This approach is quite useful when you want to load grid instances with equal predefined settings on different pages in our web site. For this purpose you can use XSL transformation to import the grid content into XML file (using StringWriter to transfer the data from the xsl definition to the .xml file). After this operation you can generate StringBuilder object and get the StringWriter instance content. Finally, simply call the Page.ParseControl(stringDefinition) method and add the control returned by that method to the Controls collection of a placeholder control. This placeholder control should reside in the webform on which you want to visualize the grid.

You can refer to this topic from the grid help as well:
Populate grid from XML

Note: the steps described above should take place in the PageInit handler.

XSL definition:

<?xml version="1.0" encoding="utf-8"?>

<xsl:stylesheet version="1.0"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:radG="remove">

  <xsl:template match="/">
    <div>
      <rad:RadGrid ID="RadGrid1" Width="95%" EnableAJAX="True"
                  AllowFilteringByColumn="True" AllowSorting="True" PageSize="15" ShowFooter="True"
                  ShowGroupPanel="True" AllowPaging="True" AllowMultiRowSelection="True" runat="server">
        <HeaderStyle Width="150px" />
        <ClientSettings ReorderColumnsOnClient="True" AllowDragToGroup="True" AllowColumnsReorder="True">
          <Scrolling AllowScroll="True" UseStaticHeaders="True"></Scrolling>
          <Resizing AllowRowResize="True" AllowColumnResize="True"></Resizing>
          <Selecting AllowRowSelect="True"></Selecting>
        </ClientSettings>
      </rad:RadGrid>
    </div>
  </xsl:template>

</xsl:stylesheet>