IMoO/loot_tables/chests/dispenser_trap.json

{
  "pools": [
    {
      "rolls": {
        "min": 2,
        "max": 2
      },
      "entries": [
        {
          "type": "item",
          "name": "minecraft:arrow",
          "functions": [
            {
              "function": "set_count",
              "count": {
                "min": 2,
                "max": 7
              }
            }
          ],
          "weight": 30
        }
      ]
    }
  ]
}