Yesterday while sitting in an exit row I noticed that the latch for keeping the tray table up had a little piece of plastic next to it. This little tab thingy prevented the latch from moving to the right but not the left. So I could still drop the tray down and use it as normal. I noticed that all of the trays in the exit row seats had these tabs just on one side. None of the other seats had these tabs.

Now this observation is not the first but one of many where some clever person tried to prevent the tray tables in the seat back from being used but failed. I have seen it done properly a couple of times but mostly failures.

When sitting in an exit row one should use the tray table in the arm rest which will not block the exit during an emergency while the regular ones will.

Have others noticed this phenomena of attempting to prevent their usage but with similar utter failure?

1) No I haven't noticed this.

2) Not all exit rows have the arm rest trays. Some are close enough to have seat back trays.

JL domestic flights had them on the back of the seat in front of the exit row. Pitch was also a lot smaller than on a US domestic flight. An exit row on JL was probaby about the pitch of Economy Plus on UA.

I have seen these too. What I have noticed is that they prevent the lock from moving in the direction of travel TOWARDS the exit so that in an emergency the passengers brushing by them don't move the latch causing the tray to drop.

Sound like you were on the right side of the aircraft. On the left side of the aircraft they would have been on the left side of the latch.

I've seen tables where there are pieces of plastic keeping the table from coming down at all... don't think I've seen what you've described. Interesting idea on keeping exiting passengers from knocking the tables down, though.

Interesting observation. I will check for that on my next flight this week.

Mystery solved. On my last flight I had an exit row and sure enough on the left side of the plane the tab was on the left side of the latch and on the right side they were on the right side of the latch. However, the center seat had nothing ... go figure.