The Kendo UI Editor does not support such functionality. However, you could achieve that using jQuery to change the elements position inside the DOM, here is a simple dojo example: http://dojo.telerik.com/@ruzhenov/APIlA
The code that do the magic is the following:
$('.k-editor-widget tr:first-child').insertAfter('.k-editor-widget tr:last-child');
If for some reason, the rendered HTML is different, you just have to use the same approach by finding the TR that contains the toolbar (in that example it is the first TR) and insert it after the last TR.
Note that this is a custom solution and I could not confirm that everything will work properly.
You could also look at the following forum thread, but it is with an inline editor: http://www.telerik.com/forums/position-of-toolbar-for-editor
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