How are you? Thank you for posting in the Community.
To ensure I fully understood your question, you would like to see the total of all sales email opened in a contact record?
If so at the moment a user is only able to see the number of email open/click in the email record as my screenshot bellow shows more information :
We currently don't have a property that will combine the number of open emails in sales, you will need to look into each email opened in the contact record to see the total of Sales emails opens.