I'm back
Oh yes, definitely sausages and cold cuts. There's loads to try - my personal preference is towards the smoky, garlicky ones.

Kielbasa Torunska and Kielbasa Slaska are particular favourites here. For cold cuts / deli, Baleron is very nice, as are the smoked hams and the cured, smoked pork loin (Poledwica). Kabanos is lovely, but go for the dryer ones as they're almost salami-like. In a similar vein is Kielbasa Mysliwska. Boczek (smoked cooked bacon made from pork belly) is so goooood whether eaten as is or crisped up in the frying pan.
Polish cheeses are so-so, but a good ser Tylzycki is very nice. There is also a hard sheep-milk cheese called brynza, but it's something of an acquired taste. And there are some nice cream cheeses to be had.
Herrings of all sorts... I rather like the fillets in cream sauce.
Pickles can be a minefield. I'm not so keen as I find many of them either too salty or too sharp for my taste. But I do like sauerkraut every now and again.
If you can get a good sourdough rye, then that's worth it as well. Besides, it goes a treat with all of the above.
HTH