Yes, the arrow indicates water flow direction.
Don't know what kind of RV you have but usually the output of the Everpure goes to a goose neck water spout next to the kitchen sink faucet. So you're only using filtered water for drinking and cooking, not dishes, wash water, or rinsing off things. And the ice maker.
After the water spout, the plastic pipe goes to a shut off valve, then onto the ice maker valve behind the refer.