Spam on yahoo mail

On iPad, how can I delete bulk messages without them openingnon the screen?

Just click edit - and then highlight the ones you want - and then click delete.

When I hit edit and then highlight or check off the messages they open as I do so.

You can take your finger and swipe to the right on the message in the list - that will bring up the delete button and then click delete. I don't think it opens that way just don't 'click' it with your finger first - it's a swipe action only.