Hi,
Indeed, this confirms that this is not the same problem. You can see that there are several minutes between each order of the same user. So it's not possible that the problem comes from the customer clicking several times on the finish button at the same time.
Besides, you're not using PayPal Pro, so even if that was the case, the payments wouldn't be processed for the orders.
I actually don't see a problem. It's just that the customer went to PayPal, clicked on the cancel button there, then was redirected to the checkout again, clicked on the finish button again, was redirected to PayPal, clicked on the cancel button there again, etc.
Each time the user finish the checkout, an order is created.
So it's totally normal so see several time a similar order. To important thing is to only have the order confirmed after the payment.