Here is how to install UT3 mods on your PlayStation 3.
1. Unzip the file to the root directory of any memory card that is readable by your PlayStation 3. It is already in the proper directory structure but, just in case, the path and filename need to be: ps3savedatablus30086-modimportuserdata.jam
2. Boot up Unreal Tournament 3 on your PS3
3. Go to the "Community" menu
4. Choose "My Content"
5. Press the [SQUARE] button to "Import Mod"
6. Follow the directions on the screen to import it from your memory device.
Once imported you'll be able to see the map in your list of Deathmatch maps. You'll be able to host the map and join servers that are hosting the map. All UT3 mods install this same way. If this were a mutator it would show up in the mutator list. If it were a gametype it would show up in gametype lists, etc.