You can convert a text file created from another program to a Microsoft Excel file by using the Open command (on the File menu) in Excel. When you open a file, Excel converts the file automatically. You can also import a text file with the Import Data command (Get External Data submenu on the Data menu). When you import a text file, Excel displays the Text Import Wizard, which provides additional flexibility and options for deciding how to import the text file, and then converts the file. For more information, see the Help topic, Import a text file. Once you import the text file, you may want to change the decisions you made in the Text Import Wizard. For more information, see Change how an imported text file looks.
To be clear about terminology:
Numbers documents contains sheets.
Sheets contain tables, graphic, text, charts
There is not concept of tabs (like MS Excel).
Finally you have posted you question in Number for Mac OS X (not iOS). You will most likely get a more helpful question there. Many people in this forum do not use iOS.
Looks like I should be more careful when reading. You did post in the iOS forum (in which case I expect most people here have iOS devices). I do apologize for not being more carfeul.
Here is a link to an APPLE web page that may help you transfer the document using iTunes:
I hope this helps!