Can't find any tables after psql dump import from pgexercises.com
The solution is: Schemas, SQL for namespace.

The third line in the exercise dump is: CREATE SCHEMA cd; 

As a result, the tables are accessible by prepending cd. in front of table names.

Running \dt * with wildcard also shows all tables present, no matter the namespace. This is a good thing to run when \dt gives no result even though one expects that it should have.