Kubernetes (minikube) pod OOMKilled with apparently plenty of memory left in node
You must understand the way requests and limits work.
Requests are the requirements for the amount of allocatable resources required on the node for a pod to get scheduled on it. These will not cause OOMs, they will cause pod not to get scheduled.
Limits, on the other side, are hard limits for given pod. The pod will be capped at this level. So, even if you have 16GB RAM free, but have a 256MiB limit on it, as soon as your pod reaches this level, it will experience an OOM kill.
If you want, you can define only requests. Then, your pods will be able to grow to full node capacity, without being capped.
https://kubernetes.io/docs/concepts/configuration/manage-compute-resources-container/