Meriadoc Brandybuck's ability has you create just one Food token per player you attack with a Halfling, no matter how many Halflings you attack them with beyond the first.

Halflings attacking a planeswalker or battle won't cause Meriadoc Brandybuck's ability to trigger.

Food is an artifact type. Even though it appears on some creatures, it's never a creature type.

Whatever you do, don't eat the delicious cards.

You can't sacrifice a Food to pay multiple costs. For example, you can't sacrifice a Food token to activate its own ability and also to activate Maraleaf Rider's ability.