Automatically unlock iPad mini 5 upon pickup
Unlike the recent crop of iPhone and iPad Pro, iPad mini 5 doesn't feature Face ID. It comes with a physical Home button with a Touch ID built-in. Neither does it feature Raise to Wake setting, which automatically wakes the screen when you pick up the device.

So there's no way you can configure it to unlock without a physical intervention required from your end.

The best/fastest you can do it to configure it to unlock just by resting your finger on the Home button. Go to Settings → General → Accessibility → Home Button and enable Rest Finger to Open.



This way, you can speed up the process of unlocking your iPad and making it ready for use. Once the setting is enabled:


If your iPad screen is turned off, simply pressing the Home button will both wake and unlock it.
If your iPad screen is awake, just resting the finger will unlock it and get it ready to use.


The aforementioned (picking up the iPad, while keeping your registered finger, generally thumb, on the Home button) is the fastest you can go from picking up your iPad to taking it to the unlocked usable state.

Additionally, with the screen awake, you can swipe left to launch the Camera app. The iPad mini 5 also works with Apple Pencil 1st generation. Thus, tapping on the screen with the Apple Pencil will directly launch the Notes app with a new note.