How can I use my important excel data in the form?

I read all of your guides but all of them explains How to upload data , Not the way apply them to the form.

Also it will be great if you can explain more about importing excel data to the form.

(I want to add questions to the form which is in the excel sheet.)

Thank you. 

It is possible to import CSV or excel data to your form. You can do it with our import data app:  https://apps.jotform.com/app/import_data

You can find how to do it with the link below:

https://www.jotform.com/help/308-Import-App-Easily-Import-Your-Excel-or-CSV-Data-into-JotForm#_

Also, what do you mean with applying data to form? Could you please explain a bit more?

In addition to what my colleague suggested you might be interested in the spreadsheet to form widget. It allows you to populate a form from a spreadsheet:

How to Use the Spreadsheet to Form Widget