Yes, you need to file a new 体检表. If your 体检表 for 第一份485 is less than one year, you may just ask the Dr. to give you a copy of it for the second I-485.
But if your 体检表for 第一份485 is over one year, you need to do the physical exam again (of course, you may use some results from the 第一份体检表 such as some kind of vaccine injection).