Whether or not you are over-reacting to a minor cosmetic blemish, contributors here cannot judge. Only you can make a determination as to whether or not the blemish is acceptable to you. With that said, the vast majority of new devices are absolutely pristine when unwrapped for the first time.
If you have purchased your iPad directly from Apple, in most countries/regions you have 14-days within which you can unconditionally return an undamaged item for exchange or refund. If applicable - and you have any concerns whatsoever - you might be well advised to make use of the opportunity while it is available to you. Upon expiry of the 14-day period, any defects may be remedied under the standard warranty.
Consider visiting the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be delighted to assist:
Genius Bar Reservation and Apple Support Options - Apple