Tom was exactly right. I was trying to restore the dump file into an already created table structure that did have three foreign key constraints. I removed the primary key constraint to speed up the load, but was not aware of the memory usage of the foreign keys. I dropped the table and ran the pg_restore again, and it is running currently and behaving nicely at constant 13Mb of memory. It will probably take some time, but I think it is working fine. Thanks for the help.
