Why are tray tables stowed on flights during takeoff and landing?

'Please ensure your seat backs and tray tables are fully upright and locked.' Are you familiar with this cabin-crew messaging while flying? Most people wonder what a seat's position or a tray table has to do with a flight's takeoff and landing. At times, unruly passengers even ignore the instructions of flight stewards to position themselves according to their liking, sidelining the importance of such messages. It's crucial to understand that all of these simple safety checks, like fastening the seat belts, switching off electronic devices, keeping window shades open and more, are important during a flight. Here's what you need to know about why the cabin crew insists on locking the tray tables. Captain Steve, a pilot and YouTuber, recently explained why tray tables should be stowed. 

For safety
The Federal Aviation Administration recommends evacuating the passengers within 90 seconds of an emergency. The passengers need to be able to get out of their seats and make their way to the exit without being impeded by a tray table. Any delay in evacuating the aeroplane could even lead to loss of life.
All airlines follow this mandatory safety protocol to make the exits open and clear in case passengers need to be evacuated. International aviation rules recommend removing all obstacles from the cabin during aircraft take–off and landing.

Upright seats
The seats inside the aeroplane should be upright during takeoff and landing in case an emergency requires a swift evacuation. Moreover, the passengers should wear seatbelts. These two aviation rules ensure that the exits are clear to evacuate passengers in an emergency.