The FDA complaint food-safe resin topcoat will withstand heat up to 135 degrees Fahrenheit (safe for a cup of coffee or a hot plate, but not a hot pan from the oven). If you can hold it in your hand, it’s safe to put it on your tray.
You can wash your tray (if needed) with mild dish soap, but don’t ever fully soak it in water or use anything abrasive to clean it.
I recommend using ammonia-free glass cleaner if you need to clean the shiny resin topcoat.
Every once in a while, if the wood part of the tray starts to look dry, you can oil it with a small amount of olive oil. Be very careful not to get any oil on the resin, oil can dull the finish over time.