I have a 1.9x1.7 nodule in axial dimension. is that big?

Size is relative: As with all things in life, size is relative. Whether a thing is big or small depends on what it is, what it's doing there, whether it's growing or shrinking, whether it's getting in the way of something else, etc... One's primary care doctor who knows the whole story, can best help figure things out. Details matter! For a nodule in the body, 1.9mm may be small whereas 1.9cm may be big.