I'd say that, if you are playing so quietly that you can hear the keybed, change to headphones!

I've got a G70 next to my home BK9, there's not THAT much difference between the two.

But, if you want, try making sure it's not the stand you have it on that's contributing to the vibration. I have mine at home on a music production desk, and it's VERY solidly supported, no bounce, no nothing. But it's worth slipping some rubber shelf liner material under the arranger's feet if you want to stop any playing vibration getting into the table.

Truth is, play a B3 not switched on, or a dummy piano action, or a Rhodes or Wurli not plugged into an amp, those actions are far from silent. If you can't play loud enough to overwhelm the keybed, try a nice pair of isolating closed ear headphones.

Or crank it!