This is an expansion board for Nextion Enhanced HMI display. Enhanced and higher version Nextion displays supports 8 GPIO and this expansion board can be used to control Nextion.
The board has 6 buttons, which include Esc, Enter, Left, Right, Up, Down. Also, buzzer and leds are included.
An application example can be seen onthis video.
More information is available on the website of Itead.