Beginner Gardening: Are my big max pumpkins ready to harvest, 3 by EDKhoo

EDKhoo wrote:
This is my first pumpkin patch.I planted the seeds around mid may so they have been growing for around 3 months now. I was wondering whether I can harvest it now or have to wait. The first image is of my pumpkin patch around half a month ago, now the foliage has significantly reduced. The second picture is the first pumpkin that formed. Given the size of the pumpkins do you recommend cooking it or being used as a decorative item.