This is not something I normally do, but sadly I feel compelled to communicate issues with the very popular Baby Bjorn high chair.
We purchased this item from Tesco for our son - enticed by the aesthetic combined with positive feedback from friends.
However, our particular high chair was able to 'spring' open and my son fell to the stone floor below, landing straight on his head, before my wife could catch him.
For clarity, there is no way that this should be possible. There are no shades of grey. The chair is either locked, the tray table thus being upright, or it is unlocked, and the tray table is down.
My son had been sat in the chair for five minutes before malfunctioning.
I would urge all current users of this item to return to Baby Bjorn and any considering to buy in the future to not consider this as an option under any circumstances.
Note - in the US they now sell the same chair with a harness. I wonder why!