Can pgadmin manage large objects?

pgAdmin has no special LOB support. However, you can use standard language features in any client interface to control them. See http://dave.webdev.pgadmin.org/docs/1.4/pg/largeobjects.html for a link to these functions.

This leads to a number of important limitations. You will get an escaped string when you pull a LOB from the database. You cannot, say, pull the file and display it as an image or the like.