DavidR
2
Open the chest, Infected Files section, highlight the file/s (select) you want to delete, right click and select delete. That will get rid of those you selected.
Warning ensure you are in the Infected Files section, only delete those more than 4 weeks old, check the Transfer time column that is when they were sent to the chest.
Normally it is suggested you wait at least three weeks and then scan them within the chest, if they are detected still then delete. Because you have 500+ this task is likely to be very long and since you haven’t done it for some time and there is/was no noticeable effect of the files being in the chest it should be reasonably safe to miss out the scan and delete them.