Can't imagine why you would have five RG-6's coming in, but if the three are properly bonded to the ground wire it shouldn't make any dif in the ground. Ground blocks are cheap--about $1.75 each.
One big one would look neater, but if you mounted them in a straight line it could be made to look neat. I always like to stub up a piece of 1/2 inch conduit and mount the ground block inside a weather proof plastic receptacle box to protect it from being hit by weed eater, etc.
In my opinion, you can never have enough grounding, and if these are the cable entry/demarcation points, I am pretty sure code requires them.