The first series of rooms look more like a warehouse than a museum. There are several rooms that just have things randomly arranged, not explained, and all one can do is peek into the metal grating. There were plenty of religious relics and icons, and other symbolic items.
The outer courtyard section displays vats, cars, anchors, and other historic objects that are all related to Malta. Some were significant because of the age and date that these items were found. For example, I think the anchor was significant because it dates all the way back to Roman times.
Finally, the indoor gallery. There are plenty of old art displayed here, most of them being religious in nature. There are also old musical instruments, old carriages, and rooms furnished in a historical setting.
Overall, I liked my visit. It may not be a huge museum, but there are plenty of things to see here. Visit it if you find yourself in Rabat.