The psql command with a "create table" statement can be used to create a new table.

If using the default posgres user account, I typically go with the following command.

sudo -u postgres psql --command "create table mytable (id serial primary key not null, date_created timestamp, firstname varchar(30) not null, lastname varchar(50) not null)"

If you have created a user account, the -u or --username option and --password flag can be used.

psql --username johndoe --password --command "create table mytable (id serial primary key not null, date_created timestamp, firstname varchar(30) not null, lastname varchar(50) not null)"

Better yet, you can setup passwordless authentication using the hidden .pgpass file and then connect without the --password flag.

psql --username johndoe --dbname mydb --command "create table mytable (id serial primary key not null, date_created timestamp, firstname varchar(30) not null, lastname varchar(50) not null)"