How to copy certain tables from one schema to another within same DB in Postgres keeping the original schema?

You can use create table ... like

create table schema2.the_table (like schema1.the_table including all);

Then insert the data from the source to the destination:

insert into schema2.the_table
select * 
from schema1.the_table;

You can use CREATE TABLE AS SELECT. This ways you do not need to insert. Table will be created with data.

CREATE TABLE schema2.the_table
AS 
SELECT * FROM schema1.the_table;

Simple syntax that works as of v12:

CREATE TABLE newSchema.newTable
AS TABLE oldSchema.oldTable;