We've run into this problem before. When asking if I could delete it, the response I received was:
"Definitely you can delete this log. What this log does is store health and wellness data. What we need to do is monitor and see if it fills up again. If it does there is a solution to prevent that log data from being written to."
As deleting it seemed to resolve our problem, and it hasn't filled up again since, no further steps were taken.
