You are storing 5 potentially large tensors and the memory requirement depends on all operations you are performing on this data or in your training script in general.
Could you describe your expectation, i.e. why is an OOM error not expected? Was the core working in another form, i.e. are you seeing the OOM only by storing these 5 tensors? If so, how are you processing them? Did you try to check the memory usage before the changes and afterwards?