Tables make your life easier

table <clients> { 192.168.2.0/24, !192.168.2.5 }

the file /etc/clients

192.168.2.0/24
!192.168.2.5

in /etc/pf.conf

table <clients> persist file /etc/clients

pass inet proto tcp from <clients> to any port $client_out flags S/SA keep state