What you are talking about is not RAM, is mass storage. However, with 73+ megabytes you have plenty of mass memory free. I don't advice to uninstall any other package because you could have problems with your unit, at the point to brick it and need to reinstall the firmware.
However, if you like you can confidently uninstall tutorial-home-applet, but you better leave alone mplayer, which is needed by several audio/video apps (maybe also Canola).

Best tip to leave your mass memory uncluttered is to keep your media files (audio, video, ebooks, whatever) in the sd cards instead that into the (very limited) default internal flash memory. I.e. try to keep empty all the directories under MyDocs.