A flashing screen could be caused by various factors, such as a graphics card issue, a driver issue, or even a hardware issue. However, as you mentioned that the memory load was high when the issue occurred, it is possible that the flashing screen could be related to a memory issue.

Adding more memory could potentially help alleviate the issue, especially if you are running memory-intensive applications. However, before adding more memory, it would be a good idea to run some diagnostics to determine the root cause of the issue.

You could start by running the Windows Memory Diagnostic tool to check for any memory-related issues. You could also check for any driver updates for your graphics card and ensure that your system is up-to-date with the latest updates and patches.

If the issue persists even after running diagnostics and updating drivers, it may be necessary to contact Dell support for further assistance.