I feel.like all the Dumb Beasts are the animals you might eat (cows, sheep, pigs, fish etc.) or hunt for food (stags, some bears, etc) but not for sport (lions,.foxes, etc.) whereas all the Talking Animals are ones you would not (horses, mice, ravens etc)

Posted by: @icarus

I feel.like all the Dumb Beasts are the animals you might eat (cows, sheep, pigs, fish etc.)

Not necessarily so. There's a Talking Lamb in The Last Battle. 

Posted by: @icarus

whereas all the Talking Animals are ones you would not (horses, mice, ravens etc)

As for mice, we're made aware in Prince Caspian that there were no Talking Mice in Narnia until that group of mice ate away the cords that bound Aslan to the Stone Table, and were given the gift of speech as a reward for their kindness. There's also a brief reference to Talking Rats in The Silver Chair, but we're not told whether they were given that status at the beginning of Narnia or earned it later! 

I always wondered why Lewis doesn’t make reference to many talking songbirds in Narnia. There is a mention of a robin in The Lion, the Witch, and the Wardrobe, although I am not sure if it was a talking bird. There were also the singing birds which brought food to Ramandu, which was a beautiful part of Voyage of the Dawn Treader.  Otherwise the small birds apparently weren’t mentioned very often, although they may have been present. Maybe some thrushes or finches would have added some natural music.  But he was not such a big fan of classical music either, which was kind of sad. He did think of having large beautiful birds such as eagles and owls, but they are not birds that had musical voices.  But I guess we can assume that were many different kinds of birds in Narnia even if only a few are mentioned.