Hello Bill,
Welcome to Communities.
As daphnissov said, ESXi/vCenter doesn't add disks to a VM unless you/someone/something else added told them to add them.
Did you perchance create this VM from a template of ova that has multiple disks?
Does this VM serve a function that is intended to temporarily hot-add disks such as a backup-proxy?
I would strongly advise validating the identity of any disks before considering deleting them as they might belong to other VMs - you can do this simply by looking at the path to the vmdk from the drop-down information on each hard-disk.
Bob