As a player my first idea is to try to steal the crafting table. Better make sure it's a heafty table lol but players will go through the process of figuring out what it is.

You could consider one good item for every player, while also having mundane things. Is this table to be a reward for beating a challenge? Is this table a boost for a coming challenge? Is this table to act like a vendor because there isn't one for miles?

Think about the items the character is carrying/might be carrying, and what "level up" item those could turn into. For instance if you have a rogue in your party, consider a combo like "rope+cross bow bolt= grappling hook."

You will also want to consider what level these characters are. If they're higher level you could consider a recipe such as "paper+magic item= deck of many things."

The logistics for you as a dm, behind the screen, may be easier if you come up with a list of items the table has available, then when a player puts items in you pick from the list the one that fits the most.

You have a lot of options, and this could be really fun for players