Just from what I see it does look like it was chipped by man for a tool that maybe was only used for a moment or it could be a piece that was tested for knapping.JMO
I agree with the opinion that it is worked, and it is a very large tool or Blade.
It looks to be made of a light colored Rhyolite (I want to check pictures of local New England lithic samples to see if the light color and spotting is patination or natural cortex color)
I like the term Creek Chatter, but It likely doesn’t apply here. And, it does look like it was made from a large flake.
Here are a few pictures of lithics that have similar characteristics of the artifact in your post.
The first is a photo of a page from Boudreau’s, A New England Typology (Of Native American Artifacts) of a group of Late Paleo -HOLCOMBE Projectile Points all found at the same site in Androcsoggin County, ME.
Here are a few photos of flakes and a tool from my collection -all found in Southern New England. (keep in mind that I cleaned these with a toothbrush):
These are just my observations, but I admit that I have much to learn and a long way to go regarding lithic materials.
Charlie has a very strong grasp of Petrology, especially specific to New England, so he may be able to speak to this with more confidence.