My sturdiest knife, a big bag of road salt, and a book.

If I get to choose to appear in civilisation, I’ll probably bring a mathematics handbook with the last two millennia of formulae. If unknown where I get dropped, probably a mechanical engineering handbook.

I have a decent chance surviving to civilisation with the knife, I can pay my way with the salt for a bit, and I might pull off advancing industrialisation in spite of slavery.