This was a bug that they found and fixed yesterday. From Bubble:
Between April 16 and May 9, Page Load workload was not correctly displayed on the pie chart; it included erroneous entries starting with “Deleted Page: ###”. The good news: All WU were calculated and billed correctly. The bad news: This mistakenly labeled data will persist though June 9 on the pie chart since it shows 30 days worth of data.
What @msgiblin noted. There should now be a label on this page explaining just that. Please be in touch with our support team if you need help diving in further.