Yes! Keep in mind that in order to delete slides in a lesson, you cannot have any active CODES from that lesson. If this is a paid lesson you downloaded, please first make a duplicate by going over the lesson, selecting the three dots and selecting duplicate. This way you'll have your edited version and you'll keep the original version as is.
Go to your Library. Select the lesson you'd like to edit.
Select the slide you would like to delete and press the Control button on your keyboard to select the additional slides.
Select Delete Slide on the top.