The problem with NJ laws is that they are not proper laws at all! The law says something like you are allowed to carry a knife that is "appropriate" for the circumstances. The problem is that one is then at the mercy and whims of whatever cop and judge one might encounter. In sum, it is largely a notion of whatever level of risk exposure you feel is acceptable from a legal perspective.
I believe I heard Evan Nappen give a talk in which he said that there is case law stating a simple locking knife with blade length around 3in (e.g., a Sebenza) is ok. He actually said that "the state has the burden of proof". Assisted-opening knives or anything too loose are likely to be problematic and you'd have the burden to prove that you're innocent. (Twisted premise on constitutional rights of "assumed innocent until proven guilty".) Remember that even if a knife is ok from a legal perspective, cops in NJ just love to make people's life hard, and having to deal with it in court is bound to be expensive. These days I just stick to Victorinox SAKs and classical folders (e.g., Opinel, MAM) because they are easily recognized and it is really hard to argue against their utilitarian nature.
When I go hunting is a different story, as I pretty much carry whatever I want regardless of size. Hunting, and the other equipment in the car, provides the legal justification. In addition to multiple knives, I usually carry a machete to handle the thorny bushes in my area.