how to transfer data files from outlook into outlook web appl with 365

I have MS Office 2010 prof Plus.  Bought MS Office 365. Then went on setting of the Exchange sytem for the Outlook Web application.

So a new acct got created into my desktop outlook xxx@xx.onmicrosoft.com.

So what I did I started moving the files of Outlook desktop into the area of this new acct onmicrosoft on the same outlook desktop.

Then by looking onto the outook web application I started seeing this folders come up and synchronizing.

BUT

Suddenly

Two files of Data Files got created into the desktop Outlook.

Question should not be a way to export the whole Data File data into the Outlook web application?

I can start all ver again if someone got a better way but all I saw was export files and import but where from and to where I am supposed to be working in the same desktop outlook!!