Setup > Customize > Accounts > Account Teams > Team Roles
Team Role Picklist Values: You can create new, edit, reorder, replace, printable view account team role.
Account Team Role Picklist Values > New
Add one or more picklist values and each value create own line and save.
Team Role: We have added Test Sales Rep in the Account Team Roles.
Account Team Related > Add
Team Role: Test Sales Rep added to the team roles.