Hi,
That error log is actually the apache server log, not the PHP error log.
We would need the error from the PHP error log to tell you what to do.
Regarding the import, it's most likely because the file is too big, or because the CSV data contains files/images URLs and that the import has to download all of them during the import and the limitations put in place by your hosting company on your server doesn't allow the import process to run that long.
But we would need the fatal error message to confirm that.