It is possible that you have inserted the tables into a schema that is not in your search path, or the default, ie, public and so the tables will not show up using \dt. If you use a schema called, say, data, you can fix this by running,
alter database <databasename> set search_path=data, public;
Exit and reenter psql and now \dtwill\dt will show you the tables in schema data too.