public void GenerateDocument()
        {
            //Retrieve the datatable with a a helper method
            DataTable dt = GetData();
            // A list of the mergefield names in the template file
            string[] fieldNames = { "ProductNumber", "ProductName", "ProductPrice", "ProductImage" };
 
            // Name of the template bookmark that marks the repeatblock
            string repeatBlockName = "ProductRow";
 
            WordTemplate wt = new WordTemplate();
 
            // Open the template document
            wt.Open(@"..\..\WordTemplateFiles\InsertImageTemplate.docx");
 
            // Set the repeat block by providing the data source,
             // a list of mergefield names in the proper order, and
             // the name of the repeat block bookmark
            
            wt.SetRepeatBlock(dt, repeatBlockName);
 
            // Call process() after setting the data source and/or repeat blocks
            wt.Process();
 
            //Save the output to the desired location
            wt.Save(@"..\..\WordOutputFiles\InsertImage_output.docx");
 
            return;
 
        }

 Template: InsertImageTemplate.docx

Output: InsertImage_output.docx