I'm just wondering if wouldn't be good to know what mod/admin, add or edit the dumps made for the site?

I mean, it will be good to know such thing and eventually to know with which mod/admin a dumper need to talk or P.M. about anything he wants to.

Moreover, it will be helpful even for the mods themselves when they want to know the same thing.

Thanks in advance.

i think that would be great

Actually, this is the best idea I've seen written in redump.org

Actually this information is already available in the recent changes rss feed. Try to open it in Opera or IE; Firefox doesn't seem to recognize the relevant "author" (which is in our case the mod who changes/adds something) field.
Inconveniently, you'll have to update it regularly so you won't miss any changes. A more permanent solution - maybe a "changelog" on the dump page itself - would definitely be advantageous.

It will takes just a little change to the actual system, I mean, if each time a mod/admin needs to add or edit x dump, they just will have to add their names to the dumps' page they added/modified.

Of course a complete "changelog" site itself will be great, because there will be not only the names from the mods which made the additions/modifications, there will figure all the changes themselves; but this will take some more time.

You can monitor what changes are being made if you subscribe to the RSS feeds. They will show who made the change (except for firefox...for some reason it's rss reader won't show that info).