Lenovo TB-X103F User Manual page 16

File transfers: Select this mode if you want to transfer media files such
as photos, videos, and ringtones between your tablet and the computer.
Photo transfer (PTP) : Select this mode if you want to transfer only
photos and videos between your tablet and the computer.
MIDI: Select this mode if you want MIDI -enable applications on your
tablet to work with MIDI software on computer.
USB debugging : Select this mode to enable debugging. You can then
use tools such as Idea Tool on the computer to manage your tablet's
data.
Installing APK
Follow these steps:
You need to set the device to allow installation of apps obtained from
unknown sources.
Go to Settings > Security, turn on Unknown sources and tap OK.
Copy the APK file from the computer to the device in "File transfers"
mode.