pixel_player77514891 There is no direct way to select the amount of cargo to be sent. Ships in Seaport were always fully loaded. So the only strategies which might help you are using your ships tricky as already said.
You could use a very small ship. For your example, La Pensée will transport just 7 gifts which will be traded to 3 or 4 drums. It might be handy to keep a few old 1-slot ships instead of putting them in the museum for this so you can switch them in when needed.
You could also use a ship (or several ones or even use Drew Carrymore captains) which have as much cargo as your stock of gifts subtracted by the ones you want to send to the merchant. For example, if you have 123 gifts and want to trade 6 of them at the merchant for 3 drums, try to find ships and maybe captains which can transport 117 gifts. There is also a difference on cargo multipliers, depending on where you will send the ships with the spare gifts, either the merchant or the market place. If you are very quick in sending ships, send the ship(s) with the 117 gifts to merchant or market place, send another ship with the other 6 gifts to the merchant and immediately cancel all the other ships with the red buttons in the fleet list window on the map (you have 30 seconds for this), this way the 117 gifts will go back to your warehouse and still can be used.
Or decide which contractor items from the merchant you will need next, trade them at the merchant and to stay in your example, if you have around 6 gifts left over, send those one to the merchant to get the drums.
If even after end of this event in nearly a week gifts or contractor items are left in your warehouses, you could either delete them by tapping them in the warehouses or trade them at the market place if the amount left is worth a travel for you.
