From the reviews I've read I think it could be in one position, but I've also read that you can move it to the side, just not back and forth, although according to Gilbert at GSTP they're changing these out, so it might not be a problem for long -

"If there’s an initial gripe to be had with the new upper class suite, it would simply be the proximity of the large tray table to the body. It swivels nicely allowing you space to eat on the side, but if you’re on a laptop and working away, you may need to do a few crunches or crash diet to ensure enough space if you’re reclined in the slightest. As I write this, I feel a need to hit a gym, fast. Fortunately, it sounds like these are being swapped out, quickly on new deliveries."