The ESP is created automatically by some tools on disks over a certain size. Apple's Disk Utility does this, for instance. As psusi says, it's not needed for a non-boot disk (or even a disk with a bootable OS, if its boot loader resides elsewhere), but it also does no harm. A 200 MB ESP is 0.01% of the total space on a 2 TB disk. This is a trivial amount, and to reclaim this space, you'd need to erase and re-create your first partition or resize the partition backward from its starting point. Either operation will be a hassle, and could result in data loss. Thus, I recommend just leaving it in place unless you have some compelling reason (say, to keep partition numbers aligned across multiple backup disks) or if you need to delete and re-create that first partition for other reasons.