Tampere is the second biggest city in Finland, so there are great places for shopping like department stores & shopping malls. But if you want to skip those huge places and go for more individual stores, I could recommend you a street in the city centre which leads to the market place (Laukon tori) by a lake called Pyhäjärvi. That street is called Aleksis Kiven katu and it's full of nice small shops mainly interior decor orientated. It's a haven for me!
Domdom has beautiful pieces from many Scandinavian decor brands. I could spend there a whole day! Also Copper up in the corner is pretty unique - it's a lifestyle boutique with a champagne bar!
Found also a Vintage market place full of everything retro from clothes, household items to cars(those probably were not for sale!).
Aleksis Kiven katu towards the lake and market place.
Enjoy the Finnish summer and freshly picked peas!