Hi I want to imlpement menus with submenus. Submenus should be in 3 <td>.Means it should be in 3 columns.
<Menu>
<submenu1>  <submenu4>
<submenu2>   <submenu5>
<submenu3>   <submenu6>

<Menu>

The below example is for a vertical separator but you could do something simliar using <hr> tag for horizontal separator

Implemented this using the MVC extensions like:

items.Add()
                .Encoded(false)
                .Enabled(false)
                .HtmlAttributes(new { @class = "separator vertical" });

CSS:
/*add vertical menu separator*/
.k-menu .k-item.separator.vertical
{
    padding:0px; 
    margin:0px; 
}
    .k-menu .k-item.separator.vertical .k-link:after
    {
        content:"|"
    }

For a menu separator I just use a disabled <hr>:

<li disabled="disabled"><hr /></li>

Yes, it does, an example will be added to the documentation soon. I've posted an example in your forum post:
http://www.kendoui.com/forums/ui/menu/adding-menu-using-web-service-best-practices.aspx

does the append() support adding images to the menu item? there is not much documentation on what all fields are supported for the menuitem when we call append() or insert*() etc. we just discovered 'url' is supported by trying it out ourselves.

we would also need some property like 'content' where you can add html content that goes inside the line item. (unless expectation is that we use jQuery ourselves to do this). 

Please post a menu example in the documentation using an image. Thank you,

Thank you for the suggestions, we will consider adding them to Kendo UI. 

Actually Menu widget supports icons as it is, you just need to add an IMG tag inside the LI element. Or you can add sprite containers by using a SPAN with class="t-sprite" instead of the image.