If you have the trashcan enabled in your account settings, you should be able to use it in any view. In Grid mode, it will be at the far right of each row, and in Multiline mode, you will have to toggle the task details open to get to it. However, as long as you have a fairly recent browser, there is an even easier way. Just hover your cursor over the check box of any task, and a popup will appear with the option to delete the task.