As above - young bird for eating is a squab.
About 1lb weight, its prized as a bird that has never flown so the meat is exceptionally tender. Usually the birds will be about 4 - 5 weeks age. Roast / stuff and treat as you would chicken. Bit seasonal - normally available fresh through the summer, but can be a frozen product.
And in case the fancy takes you, you can also get a squab chicken - mostly sold as poussin - which is a 4 - 6 week old bird.
Or did you mean what is a good name for a baby pigeon? - try: 'Walter' or 'Bob' . . .