If you want to stop Windows 10 from automatically switching to the tablet mode, then it can be done using Settings app and Registry Editor.

Want to fix a touchscreen that stops working in tablet mode on Windows? Uninstall and reinstall related drivers or tweak the Registry.

Tablet mode is still a joke in Windows 10 but I could maybe be convinced to upgrade if it would automatically switch to tablet mode for full screen start and apps like Netflix when I connect it to ...

Disable Windows 10 Tablet mode. The easiest way is to Select the Action Center icon in the lower right-hand corner of the screen, then click Tablet mode. Update Windows 10.