[wp-testers] What are these files?

[WordPress]

They look like MySQL error dumps to me.  I had the same types of files  
show up on my server a few years ago when I was working with another  
program.  You *should* be able to pass them to your host and they can  
look at them and tell you what the problem is.  (They contain what  
looks like a LOT of gibberish, but it's actually a lot like the error  
codes you see when your PC pukes on you.)  but someone else might be  
right - they could be Apache (but the ones I've seen are usually "pid"  
files not "core.**" dumps)

Your host will know what to do with them.

~Shelly