The following code snippet can be used for modifying the inserted table by the dialog until this is implemented:

<telerik:RadEditor ID="RadEditor1" runat="server">
</telerik:RadEditor>

<script type="text/javascript">
	var commandList = Telerik.Web.UI.Editor.CommandList;
	var replaceTable = commandList._replaceTable;
	commandList._replaceTable = function (table, editor, args) {
		var insertedTable = args.tableToModify; //The new table created by TableWizard dialog which will be inserted
		
		//Here the inserted table could be modified
		insertedTable.style.backgroundColor = "red";

		var oldTable = table; // The table which will be replaced if exists
		replaceTable.call(this, table, editor, args);
	};
</script>