Or rather, how heavy can the airplane tray table support?
I am afraid that if I use one of those flight pillows (https://familyshop.notyourchild.com/products/travelsky-inflatable-travel-pillow-foldable-for-airplanes-train-sleeping-flocking-pvc-soft-head-neck-rest-support-travel-pillows-2) and assert my upper body onto the tray, it might break.