El codigo se quedo de la siguiente manera
Código HTML:
<!--...-->
function toggle(obj,n)
{
var item = document.getElementById(obj);
if(n == 0){ item.style.display = 'block';}
if(n==1){ item.style.display = 'none';}
}
<!--...-->
<tr>
<td>
<div id="Menu1" onMouseover="javascript:toggle('MenuProd',0);" onMouseOut="javascript:toggle('MenuProd',1);">
<a href="&.html" target="contenidos">
<img src="../../&/&/&/&.jpg">
</a>
</div>
<div id="MenuProd" name="MenuProd" name="MenuProd" style="display:none;">
<a href="&/&.html" target="%"><img src="../../&/&/&/&.jpg"></a><br />
<a href="&/&.html" target="%"><img src="../../&/&/&/&.jpg"></a><br />
<a href="&/&.html" target="%"><img src="../../&/&/&/&.jpg"></a><br />
<a href="&/&.html" target="%"><img src="../../&/&/&/&.jpg"></a><br />
<a href="&/&.html" target="%"><img src="../../&/&/&/&.jpg"></a>
</div>
</td>
</tr>
<tr>
<td >
<a href="&.html" target="%"><img src="../../%/&/&/&.jpg"></a>
</td>
</tr>
<tr>
<td>
<div id="Menu2" onMouseOver="javascript:toggle('MenuMember',1);" onMouseOut="javascript:toggle('MenuMember',0);">
<a href="&.html" target="%"><img src="../../&/&/&/&.jpg"></a>
<br />
</div>
<div id="MenuMember" name="MenuMember" style="display:none;">
<a href="&.html" target="%"><img src="../../&/&/&/&.jpg"></a><br />
<a href="&.html" target="%"><img src="../../%/&/&/&.jpg"></a>
</div>
</td>
</tr> El problema es que se quede el submenu