Reading Mode on Samsung Galaxy Note optimizes the screen when reading in selected apps like Readers Hub. To disable or enable reading mode on Galaxy Note 8 do as follows:
1. Open "Settings" app and go to "Display"
2. Under Screen settings, tap "Reading Mode"
3. To enable or disable Reading mode, slide the toggle button
4. Tap "Add" to add application to the Reading Mode. Note that, only some selected apps are consistent with Reading mode.