Sallie
Tumble Tots is held in Melton Mowbray, I think on Burton Road somewhere. I don't know really about groups, because I am quite antisocial, and have only just plucked up the courage to take ds to pre school 1 day a week!
Twinlakes is absolutely fantastic in the summer, and I don't think they charge for under 3's either.
There is a farmers market on a Friday morning at the cattle market, a livestock market at the cattle market on Tuesday mornings (free entry so great for looking at moo cows), a general market in the town centre on a Tuesday morning and Saturday morning, a flea market on a Wednesday morning in the town centre, and a massive car boot on a Sunday morning in the cattle market.
There is a mums and toddlers run in the Covenant Life centre on weekday mornings, but have never been so don't know whatit is like.
Failing all else, lots of rosy-cheek-making country walking!