After expanding the Tablo over-the-air TV DVR to the Apple TV last year, Nuvyyo is releasing the new Tablo Dual starting June 4. The $250 device now includes 64 GB of onboard storage — where the original relied solely on an external hard drive to use DVR functionality — but it still supports the addition of an external hard drive of up to 8 TB for those who find 40 hours of HD recording not to be enough. The two-tuner Tablo Dual costs $50 more…