Microsoft has reportedly been working on a miniature version of its Surface tablet for nearly two years, but the wait may be over. The company has just sent out invitations to a Microsoft Surface event on May 20th, with the tagline Join us for a small gathering. While that could obviously simply refer to a small gathering of attendees to see the latest device that Microsoft has to offer, it seems far more likely to be a tease for the companys latest product, particularly since Microsoft already recently refreshed the full-size Surface line of products.