Thank you for your message.
In order to accomplish exactly what you need you would need to create a lot of custom code since your request is quite specific.
Firstly you need to display your candidates and show them in inside a form ( http://www.w3schools.com/html/html_forms.asp
). In form you will have checkboxes which would represent each of candidates ID. On the other page, the one where the form is posted you would loop through the checkboxes and for checked ones you would perform your action with displaying the another list of candidates along with the textboxes. You might want to create your own aspx pages in which you would handle the post requests. ( http://devnet.kentico.com/docs/devguide/creating_a_new_aspx_page_template.htm
). You can however develop your own webpart to do the same. And for submiting the textboxes it goes the same. The saving itself will be easy using our API. You can save values inside Custom tables easily as per -> http://devnet.kentico.com/docs/devguide/custom_tables_api_examples_managing_custom_table_data.htm
This will not be an easy task and you might need to play with it for a while. What you described is more of a general ASPX web development so you might want to consider hiring someone to do so or refer to our Consulting session where we can help you directly with creating the code.