Oh dear, oh dear, oh dear.
To rephrase what you are doing:
In Form1, you have a TableLayout.
When you click on a cell, it opens an instance of Form2, which allows the user to select a text file, and an image.
When the OKbtn in Form2 is pressed, you create a new instance of Form1 and pass it the file and the image.
You then show the new Form1.
You are then confused because the information is not going back to the original Form1.
Go back to your lecture notes. Read up on instances. You need to learn this stuff!
In Form1, on cell click, do the following:
Form2 f2 = new Form2();
f2.ShowDialog();
string myFileName = f2.FileName;
Image myImage = f2.Image;
and change your Form2 to include the following:
public string FileName
{
get { return textRead.Text; }
}
public Image Image
{
get { return pictureBox1.Image; }
}