It depends on the relay.  I would hope that most relays reject something that size, because relays are not data stores.  They relay notes and other stuff from one user to another.  Last time I checked the limit was much lower, but I dont know the current per relay limits. 

 Thanks, not sure. Long form articles can be way larger and maybe less important than a PGP key. We'll see what happens! Our relay certainly doesn't have those tiny limits