The cliffs of Mustikkamaa - Great spot for a sunset picnic!
Great picnic spot: Vanhankaupunginkoski rapids. Breathtakingly beautiful rapids a stone's throw away from downtown Helsinki offers a selection of great spots for a picnic - just pick and choose the one for you!
Have a picnic at Vantaanjoki riverbank and docks - make a small dock yours for a while and have a picnic by Vantaanjoki river.
Have a picnic at Pikkukoski - peaceful, close to nature and a great viewbfrom the cliff!
Teurastamo - urban picnic spot in Helsinki. Communal barbeque, sun loungers etc...
Cafe Kokko: Great coffee and the best raw cakes in town with cozy atmosphere. http://cafekokko.com/
La Cantine: Feels like Paris in Helsinki? Yes, visit this little bistro in Munkkiniemi area. Nice place especially for lunch.
Farang: nice atmosphere and influences from Southeast Asia in Töölö. If you have to choose one dish, pick the crispy pork with palmsugar caramel - it's their signature dish. http://farang.fi/
Ravintola Kolo - a tiny place with a seasonal menu that changes weekly. In Punavuori. http://www.ravintolakolo.fi/Kolo.html
Liha-Haka in Hakaniemi market hall is all about nose to tail- thinking. Graving for some bone marrow or lungs? They have it.