MyComponent.cs

using System.Collections.Generic;
using UnityEngine;

public class MyComponent : MonoBehaviour
{
    [SerializeReference] List<IMyInterface> dataarray = new List<IMyInterface>();

    void Start()
    {
        foreach( var item in dataarray)
            item.Action();
    }

    // リストに要素を追加

    [ContextMenu("Create/Data1")]
    public void AddMyData1() => dataarray.Add(new MyData1());

    [ContextMenu("Create/Data2")]
    public void AddMyData2() => dataarray.Add(new MyData2());
}

MyData.cs

using System;
using UnityEngine;

public interface IMyInterface
{
    void Action();
}

[Serializable]
public class MyData1 : IMyInterface
{
    public string Name;
    void IMyInterface.Action() => Debug.Log($"My Name is {Name}");
}

[Serializable]
public class MyData2 : IMyInterface
{
    public int Value1, Value2;
    void IMyInterface.Action() => Debug.Log($"{Value1} + {Value2} = {Value1 + Value2}!!!");
}