<!DOCTYPE html>
<html>
<head>
<script>

function boom()
{
  document.getElementById("i").focus();
  document.documentElement.contentEditable = "true";
  document.execCommand("inserthtml", false, "<table>");
  document.execCommand("indent", false, null);
  document.execCommand("delete", false, null);
}

</script>
</head>
<body onload="boom();"><input id="i"></body>
</html>