а так ещё короче)
<script>
function show(id){
var elems = document.getElementById('sh').getElementsByTagName('div');
for(var i in elems) elems[i].style.display=(elems[i].id==id)? "block": "none";
}
</script>
</head>
<body>
<a href="javascript:void(0)" onClick="show('e1')" >1</a>
<a href="javascript:void(0)" onClick="show('e2')">2</a>
<a href="javascript:void(0)" onClick="show('e3')">3</a>
<div id="sh">
<div style="display: none" id="e1">
<table >
<tr>
<td>1</td>
</tr>
</table>
</div>
<div style="display: none" id="e2">2</div>
<div style="display: none" id="e3">3</div>
</div>
</body>