SQL Grant on - for multiple users
If you have the list of users you can just append them to the statement:
GRANT SELECT ON Abteilung TO AAR1, AAR2, AAR3;
If you do not have the list ready your best bet is to do a select on all users to generate the statements necessary.
SELECT 'GRANT SELECT ON Abteilung TO ' || username || ';' FROM all_users WHERE username LIKE 'AAR%'
Then you just mark the result and execute them in a different session.