Model:

    public  class ProjectModel
    {
        public int? User_ID { set; get; }
        public int Projects_ID { set; get; }
        public int? EPR_Summary_ID { set; get; }
        public string Self_Comments { set; get; }
        public int? Self_Rating { set; get; }
        public string Appraiser_Comments { set; get; }
        public int? Appraiser_Rating { set; get; }
        public string Manager_Comments { set; get; }
        public int? Manager_Rating { set; get; }
        public string supervisor_comment { set; get; }
        public int? supervisor_Rating { set; get; }
        public int? ID_Project { set; get; }
    }
    public  class projectList
    {
        public List<ProjectModel> projectModelList { set; get; }
    }

Index View:

<input type="button" value="Click Me" class= "btn-primary" id="btnclick" /> 

@section Scripts{
    <script>
        $(function(){
             $("#btnclick").click(function (e) {
                e.preventDefault();
                var ProjectData = []; 
                 for (max = 0; max < 300; max += 1) {
                            ProjectData.push({
                                User_ID: 1212,
                                Projects_ID: max,
                                ID_Project: max,
                                EPR_Summary_ID: max,
                                Self_Comments: "",
                                Self_Rating: max,
                                supervisor_comment: "",
                                supervisor_Rating: max,
                                Appraiser_Comments: "",
                                Appraiser_Rating: max,
                                Manager_Comments: "",
                                Manager_Rating: max,
                            })
                 }
                var projectDataList = { "projectModelList":ProjectData };
                 $.ajax({
                            type: "POST",
                            url: "/Home/SaveProject", 
                            data: JSON.stringify(projectDataList),   
                            contentType: "application/json; charset=utf-8",
                            dataType: "json",
                            success: function (response) {
                                console.log(response)
                                if (response == "Sucess") {
                   
                                }
                                else {
                   
                                }
                            },
                            failure: function (response) {
                                alert(response);
                            }
                 }); 
                 });
        });
    </script>
}

Controller:

        [HttpPost]
        public IActionResult SaveProject([FromBody]projectList projectDataList)
        {
            return View();
        }