In some games, rather than dealing cards to a player, cards are dealt to a location on the table. A player then has the option of electing to pick up the cards at their convenience. (Example: Tichu , where a player may examine their first 8 cards before taking their next 6.)
Other games involve discrete piles of cards on the table whose contents change over time due to player actions, but are treated as a single stack of cards. (Example: Lost Cities , where players create face-up stacks of like-colored cards in the center of the table from which other players may then draw.)
What if, when dealing cards from the deck, there was an option to deal to a "pile" that could then be appear at a selected location on the table? The number of cards in the pile would be visible to all players. A player could then right-click the pile, and theoretically interact with it in a number of interesting ways:
Take the top card of the pile into their hand.
Take the entire pile into their hand.
Examine the face-up contents of the pile in a separate pop-up window.
Maybe add a card from their hand to the pile?
It might also be useful to right-click a single card on the table, and tell Roll20 "make this a pile containing 1 card." That way, players could create a pile by dealing a card from their hand to the table, then other players could deal cards to that pile over successive turns.