Hi Lidia

Thank you for reaching out to us.

Please note that the official language for support is English so we will have to use Google translate to answer your questions, we apologize in advance in case there are some misunderstandings.

1. In the full version there are no limitations on the number of columns that can be imported.

2. You can link data to specific users with our plugin. To do this the table needs to be editable (so you would need to import the file, to create a manual table), and also you need to have the User ID field in the table. Meaning, if John has user ID = 5, when he logs into your WordPress site, and looks at the table, he'd only see his data if you selected the User ID column as the "User ID column" in the Editing tab above the table. If there's no user ID column, and they aren't logging into WordPress, this will not work.  

 
You can also add the placeholder %CURRENT_USER_ID% as the predefined filtering value in column settings of "User ID" column, and the table will automatically be filtered per the ID of the currently logged in user.  
You can enable the Show all rows in back-end option from the Editing tab of the table to see all entries in the back-end. You can also edit the table but if you edit the table as an administrator your User ID will be saved when you make the change so make sure to turn off the Users see and edit only own data option before editing. 

I hope this helps, do let us know if there is anything else we can assist you with.