La Prosciutteria Milano Navigli is such a great spot for both lunch and drinks. I tried their aperitivo several times and really liked the choice they offer and the price it's very affordable for Milan standards. They have several branches in the city, I only visited the one in the Navigli area, and would recommend this one.
This wine bar offers an array of delectable dishes, such as its signature boards of charcuterie and sandwiches. I'd recommend the "Tagliere Gourmet", which costs €15 and offers a selection of cold cuts, cheese, vegetables and seasonal fruit.
It's a great spot for aperitivo!