How to add data into 2 different tables with EnityFramework

Question

I would like to add new data rows with entityframworks to 2 different tables

I dont know how to do this problably because both tables Have the same Key Name

 

 public async Task Create([Bind("ProductId,ProductTitle,ProductDiscription,Price,quantity,HeaderImage,MultipleImages")] ProductWithImages productWithImages)
        {
                Guid NewProductId = Guid.NewGuid();
                string uploadPath = Path.Combine(_webhostenv.WebRootPath, "Images2");

                if (ModelState.IsValid)
                {
                    string FileName = Guid.NewGuid().ToString() + productWithImages.HeaderImage.FileName;
                    string FilePath = Path.Combine(uploadPath, FileName);
                    productWithImages.HeaderImage.CopyTo(new FileStream(FilePath, FileMode.Create));

                    ProductWithImagesDb newproduct = new ProductWithImagesDb()
                    {
                        ProductId = NewProductId,
                        ProductTitle = productWithImages.ProductTitle,
                        ProductDiscription = productWithImages.ProductDiscription,
                        Price = productWithImages.Price,
                        quantity = productWithImages.quantity,
                        HeaderImage = FileName,

                    };

                _context.ProductWithImagesDb.Add(newproduct);
                await _context.SaveChangesAsync();

// succesfully adds the newproduct data into the ProductWithImagesDb table
//---------------------------------------------------------------------------

                if (productWithImages.MultipleImages != null)
                    {
                        int imgorder = 0;

                        foreach (IFormFile photo in productWithImages.MultipleImages)
                        {
                                imgorder++;
                                string filename = Path.GetRandomFileName() + "_" + photo.FileName;
                                string filepath = Path.Combine(uploadPath, filename);
                                await photo.CopyToAsync(new FileStream(filepath, FileMode.Create));

                        var productImages = new ProductImages();
                        productImages.ProductId = NewProductId;
                        productImages.ImagePath = filename;
                        productImages.ImageOrder = imgorder;

                        _context.ProductImages.Add(productImages);
                        await _context.SaveChangesAsync();
                        }
                    }
//once the productWithImages.MultipleImages is used
//it crashes because it is a different table but uses the same key (ProductId)
//-------------------------------------------------------------------------------------
                    return RedirectToAction(nameof(Index));
                }
            return View();
        }

I know that once entityFramework sees the _context.add it tracks to that database table

Maybe I can remove the tracking so it can look for a new database Table 

I dont know to do that or if that would even be a good idea