It's a (children's) cutlery set. Or try looking for christening cutlery sets. If I wanted to buy one in a physical store, I'd probably look in department stores like John Lewis, Fenwick, Selfridge's (depends where you live). Those shops online will also have them. Or online places like Etsy or notonthehighstreet. Jewellery shops probably sell them too - H Samuel, Warren James, etc.

You could look for a silver infant cutlery set, silver baby cutlery set or silver christening cutlery set. I agree with the above statement....you might add looking into the British Coin Mint as well....they might just have.something along those lines.