Knife - cold steel ltc kukri. Cheap and effective chopper and slasher. Let me get a few more bussekin knives in my collection and that will probably change.

Book - a blank notebook, so I could keep pretending I'm a scientist.

Alky - everclear. Could mix it with some coconut or fruit juice from the island for drinking, and could use it to build a stove for cooking. I use around 8 oz of alky a week for my stove while backpacking, so I figure a bottle ought to last me a month if I don't do much drinking. So it would last at least a week.