It's too big for your mouth! You need to split it first! Need to be crafted on the Crafting Table.

After harvesting Giant Scaly Fruits on farmland, you'll get the entire block, but it's too big to be eaten. Split it on a Crafting Table under the Material category and you'll get 5 Giant Scaly Fruit Slices for each Giant Scaly Fruit split.

Plant a Giant Scaly Fruit Seed on farmland, and wait until it's ripe to obtain.