how to show stringbilder data in pdf file?

Response.Clear();
Response.Buffer = true;
Response.AddHeader("content-disposition", "attachment;filename=sample.pdf");
Response.ContentType = "application/pdf";
System.Text.StringBuilder sb = new System.Text.StringBuilder();
sb.Append("<table cellpadding=2 cellspacing=1 border=1 width=800 height=500>");
sb.Append ("<tr>");
sb.Append("<td>column-1</td><td>column-2</td><td>column-3</td><td>column-4</td><td>column-5</td><td>column-6</td><td>column-7</td><td>column-8</td>");
sb.Append ("</tr>");
sb.Append ("<tr>");
sb.Append ("<td>1</td><td>2</td><td>3</td><td>4</td><td>5</td><td>6</td><td>7</td><td>8</td>");
sb.Append ("</tr>");
sb.Append("</table>");
Response.Write(sb.ToString ());
Response.End();