Lenovo Yoga Tablet 3 have been purportedly leaking since March when it was benchmarked with a 4.4-inch display, which first made it doubtful that the listing was real.
But throughout June, the FCC documents for a Lenovo Yoga Tablet 3 850F have been made public which shows that this tablet that, who’s model name is confirmed by the FCC filings, have undergone testing for quite some time.
(UPDATE: Lenovo Yoga Tablet 3 Images Leaks)
The model name suggests that this is the 8-inch Windows version. There are currently 6 Lenovo Yoga Tablet 2 devices with their 15 to 18 hour long battery life. These 8-inch to 13-inch Android and Windows tablets were unveiled at a large event in London back in October last year, and considering their specifications they don’t really need to be replaced yet.

Lenovo Yoga Tablet 3 label from FCC
The current 8-inch Android version is called Lenovo Yoga Tablet 2 8 (830). The Yoga Tablet 3 that was benchmarked in March had the model number 870, with the first digit indicating the size. But the model who’s papers have been made public by the FCC has the model number 850F, which is on digit down from the current Lenovo Yoga Tablet 2 8 (851) with Windows 8.1.
Both the benchmarked 870 model and the FCC-named 850F have been listed as having a SIM tray. But the benchmark also suggested that it had downgraded specs from the Yoga Tablet 2 series that all have Full HD resolution. The benchmarked specs says 1280 x 800 resolution, Android 5.0.2 (870 model), a 1.1 GHz quad-core Qualcomm processor, with 2GB of RAM.
So until we get some new leaks or an official announcement by Lenovo, accurate specs will probably be up in the air.

Lenovo Yoga Tablet 3 at FCC

Lenovo Yoga Tablet 3 benchmark
– Tom Bowen