Based on the screenshots only I cannot confirm anything with certainty, but have you tried to remove the margins and paddings for the body element as well, as it is the HTML element that most often has a padding/margin which can cause such small overflow.
On the matter why the rules from your CSS class are not applied to the td element - the class is set to the table element, not to the td elements inside. It is also possible that the table cells have some default padding, you can try modifying it in your table
With this information I can only recommend that you include my CSS snippet as it is and see what happens.
//get the reference to the RadWindow
(window.radWindow) oWindow = window.radWindow;
(window.frameElement && window.frameElement.radWindow) oWindow = window.frameElement.radWindow;
//calls autosize. Call this function after the other code that resizes your content:
If you are still having this issue please isolate your case (see this blog
for useful information on how to do this) and either paste a runnable version of your page that reproduces the error here, or open a new support ticket where we can examine the situation.
the Telerik team
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