<body>
<div id="abc">abc</div><br>
<input type="button" onclick="javascript:doit();" value="Go!">
<script language="javascript">
function doit(){
var abc=document.getElementById('abc');
abc.contentEditable=true;
abc.innerHTML+='<table border="1"><tr><td> </td><td> </td></tr><tr><td> </td><td> </td></tr></table>'
}
</script>
</body>