Why does prepackaged deli meat taste better when you take each slice and "fluff" it?
This deli meat you speak of is generally made of small scraps of mechanically-separated meat that are essentially "glued" together into a solid mass by enzymes that partially break down the tissue. This processed "meat brick" doesn't really have the same texture as an intact muscle tissue, which has individual muscle fibers aligned along a "grain" that makes it pleasantly chewy. Folding/layering/rolling slices of processed meat gives it more of a texture and chew, and tricks you into thinking you're eating an actual piece of animal muscle instead of meat-flavored jelly.