The following sequence of commands will create the table test_table with OID 420, having two columns cola and colb of type int4 and text, respectively, and insert two rows into the table:

create test_table 420 (cola = int4, colb = text)
open test_table
insert OID=421 ( 1 "value1" )
insert OID=422 ( 2 _null_ )
close test_table