Names that end in son or dotter are patronymic names, based on the given name of the father plus (usually) a possessive s and then "son" for male children and "dotter" for female children. They were not inherited as permanent last names until relatively late in Swedish history.
People with surnames such as Ströbeck also had a patronymic name which they may or may not have used. Some surnames were used as permanent last names. Not all were.
Read about Swedish naming customs in this article. Ingela Martinius (a Swede living in Sweden) wrote this and it is fantastic. At the moment it won't open but hopefully she is just adding something to the site and it will be okay. She has said often that Swedes LOVE to change names.