What does signing a waiver of arraignment mean?

First and foremost, your attorney is your very best resource for answering this and any other questions you have about your case. At the very least, an arraignment is a proceeding at which a person charged with a crime is informed of the charge against him and is asked to enter a plea. Some details regarding arraignment process and procedures vary across states and according to court rules (again, talk to your lawyer). Typically, a waiver of arraignment states that the defendant has been informed of and understands the charge against him and is willing to forego the formal arraignment proceeding. Arraignment is a more critical stage in the judicial process in some states than it is in other states. Whether the waiver must be more / less detailed or more / less formal depends on the state, court, level of charge, and circumstances. So . . . (you probably know what I'm about to say) . . . your lawyer is in the best position to answer your questions and advise you. Best of luck.

I'm a Pennsylvania lawyer but I'm pretty sure it means the same thing there. Arraignment is when you are formally charged by the DA. You are informed of your rights, usually to request discovery, file certain motions such as suppression etc. If you have an attorney, he or she will take care of those things for you and should know the time limits. I have all my clients waive their arraignments.