In a food processor, combine cream cheese, parsley, dill, scallion, lemon zest and juice, heavy cream, and salt and pepper. Blend until smooth, stopping to scrape down the sides of the food processor bowl as needed.
Add more heavy cream if the mixture is too thick and salt and pepper, to taste. Blend again until well combined. Scoop until a bowl and chill until ready to serve. (Can be made up to 3 days in advance.)
To serve: Thinly slice half a red onion and cut the smoked salmon pieces in half, if they are large. Build a platter of smoked salmon, red onion, capers, and dill. Add bowl of cream cheese and bagel chips on the side.
To eat: Smear cream cheese on bagel chip and top with salmon and whatever toppings you'd like.