Q.Have You Ever Seen Garlic Bulbs Multiply Up The Stalk?
We have been growing garlic for 4 years now and never had this happen. Should we put it back in the ground to grow the little bulbs on the stalk further? What makes this happen?

Certified GKH Gardening Expert
This is just something rare that can happen in place of flowering as an alternate reproduction method. You can plant these, but they aren't as reliable as normal propagation. Eating them or using them for culinary purpose is an option.
Here is a collection of articles that will help you with garlic: