limit

Set the sizes of memory pools

$ sudo pfctl -sm
states        hard limit    10000
src-nodes     hard limit    10000
frags         hard limit     5000
tables        hard limit     1000
table-entries hard limit   200000

You can adjust those in pf.conf,

set limit states 25000
set limit table-entries 300000

or

set limit { states 25000, src-nodes 25000, table-entries 300000 }

Note: limited by available kernel memory