This isn’t a normal file either. It represents a disk partition, and is almost certainly of fixed size.
Basically the questions you are asking suggest you have no understanding of logging and filesystem structures, on Linux, and probably not, to the necessary detail, on Windows either. I think you need to hire someone with the appropriate knowledge (or present a case here as to why someone should do the work pro bono). Generally people providing free support are only interested in things that the requestor might reasonably have not known about, not in dealing with the basic debugging steps that anyone analyzing a problem needs to know.
Basically logs provide information that can help a manager to understand the way the system is operating (and may also capture information used for billing). Your statistics are only telling you that the total of all your log files is reaching the limit Either something has gone wrong with the measures used to remove old entries, or some events are occurring that are creating a lot of loggable events. In the latter case, you need to find the specific file that has become excessively large, not just the filesystem (which basically only tells you that you are dealing with a large log file) and look inside it. It will contain messages about those events. Most of the files will be plain text, or simply compressed plain text files, although newer Linux systems also have files that require a special tool (journalctl) to format them.
https://sangomakb.atlassian.net/wiki/spaces/SS/pages/31162494/Support+Services+-+Providing+Great+Debug has some information on how FreePBX and Asterisk use log files, and how they can be used for debugging, but your current symptoms aren’t enough to narrow the problem down to one due to FreePBX.
There is some information on handling the case where specifically Asterisk related log files become too large at Large FULL Log Files