How to drop many (but not all) tables in one fell swoop?

First of all, you can delete many tables in a single statement:

DROP TABLE mystuff_table_1, mystuff_table_2, mystuff_table_3 CASCADE; 

Next, you could put all of those tables into a separate schema. Add that schema to the default search_path of your user(s), so it's all transparent.

Then all you need is:

DROP SCHEMA foo CASCADE; 

If that's not short enough, create a function that executes the command.
A static SQL function:

CREATE OR REPLACE FUNCTION f_delete12() RETURNS void AS $func$ DROP TABLE mystuff_table_1, mystuff_table_2, mystuff_table_3, ... CASCADE; $func$ LANGUAGE sql VOLATILE; 

Or a dynamic PL/pgSQL function:

CREATE OR REPLACE FUNCTION f_delete12() RETURNS void AS $func$ BEGIN EXECUTE ( SELECT 'DROP TABLE ' || string_agg('mystuff_table_' || g, ', ') || ' CASCADE' FROM generate_series(1,12) g -- numbers 1 to 12 ); END $func$ LANGUAGE plpgsql VOLATILE; 

Call:

SELECT f_delete12(); 

For an even more dynamic statement:
How do I drop all tables in psql (PostgreSQL interactive terminal) that starts with a common word?

you can create a procedure to do this automatically:

Try:

CREATE OR REPLACE FUNCTION public.p_drop_tables ( p_start integer, p_end integer, p_table varchar ) RETURNS void AS $body$ DECLARE SQL VARCHAR := ''; BEGIN FOR i IN p_start..p_end LOOP SQL := 'DROP TABLE public.' || p_table || i || ';'; --RAISE NOTICE '%',SQL; EXECUTE (SQL); END LOOP; END; $body$ LANGUAGE 'plpgsql' VOLATILE CALLED ON NULL INPUT SECURITY INVOKER COST 100; 

Att