Read excel file data without saving it on the server in Angular JS + Web API

I am uploading an excel file and the data first is sent to server for server side validations in list format . If only the validation succeeds and the user submits , the file should be saved and uploaded.

But for now what's happening is , it is saving the file and then reading it from the saved file location.

        sPath = WebConfigurationManager.AppSettings["UploadFilePath"];  //System.Web.Hosting.HostingEnvironment.MapPath("~/Files/");
        System.Web.HttpFileCollection hfc = System.Web.HttpContext.Current.Request.Files;

        // CHECK THE FILE COUNT.
        for (int iCnt = 0; iCnt <= hfc.Count - 1; iCnt++)
        {
            System.Web.HttpPostedFile hpf = hfc[iCnt];
            if (hpf.ContentLength > 0)
            {
                // CHECK IF THE SELECTED FILE(S) ALREADY EXISTS IN FOLDER. (AVOID DUPLICATE)
                if (!System.IO.File.Exists(sPath + Path.GetFileName(hpf.FileName)))
                {
                    ///SAVE THE FILES IN THE FOLDER.
                    fileName = Path.GetFileName(hpf.FileName);
                    //hpf.SaveAs(sPath + fileName);
                    iUploadedCnt = iUploadedCnt + 1;
                }
            }
        }

        // RETURN A MESSAGE (OPTIONAL).
        if (iUploadedCnt > 0)
        {
            //If you update the path here, update in web config as well

            //DEPLOYMENT - comment this line
            savedFilePath = "D:/Projects/Stuart V2/Stuart UI/Stuart_V2/Files/" + fileName;

            ExcelPackage ep = new ExcelPackage(new FileInfo(savedFilePath));
            ExcelWorksheet ws = ep.Workbook.Worksheets["Sheet1"];

..... //Convert to list and Send the list data to server

I do not want to save the file and then convert and send the data . But it reads from savedFilePath

how can I overcome that ?

Also , I have been asked to avoid using toDataTable() approach to convert excel data on the fly ?