I've never flown that route so I cannot say about the meal... but the full complimentary bar service should be on AY J flights, even the short hops to ARN. Surely they have some kind of a meal, but don't know the specifics.
If you go with Eco you'll have free coffee, tea and non alcoholic beverages, and that's it, no food what-so-ever, although given the lovely "deli type bread products" AY has these days, I'm not sure if that's a pro or a con.
Unless you fly on Sunday on the "right" flight (which is A319) the plane will be E170 or E190, which means that seating is the same 2+2 both in whY and J, so the hard product is nothing to write home about (whereas the A319 is the best SH hard product Finnair has to offer).