general steps:

Create a new DataTable object to store the data.

Add columns to the DataTable to match the columns in the DataGridView.

Loop through each line in the RichTextBox and split it into separate columns.

Add a new row to the DataTable for each line in the RichTextBox.

Set the DataSource property of the DataGridView to the DataTable.

Here is an example code snippet that demonstrates this approach: 

Note that this example assumes that the columns in the RichTextBox are separated by tabs. If your data is separated by a different delimiter, you will need to modify the Split() method accordingly.