If you're doing this a lot, you may find this CSV to Tabs on Clipboard (Dropbox download) useful.
To install in your Finder > Services menu, double-click the workflow package. (You may need to click 'Open Anyway' in System Preferences > Security & Privacy).
To use,
- In Finder right-click the CSV (comma, tab or semi-colon separated) file and choose the service from the Services Menu.
- Then in Numbers, click once in a cell, and command-v to paste.
That's it! The Numbers table will expand automatically if needed.
Thanks to Badunit who helped convert the AppleScript into a service and to MacScripter contributor Nigel Garvey for posting the intrepid AppleScript handler (subroutine) that can handle all kinds of challenging situations with character-separated-values that stymy many other scripts. If for some reason this can't handle your particular files, you can also search the boards for an equally sophisticated script by Hiroto.
I find this approach much faster and more convenient than the built-in Numbers import. Among other things, I like being able target exactly where the data goes in an existing document by simply clicking the "upper left" cell of the range where I want it.
SG