Is there a good emacs mode for displaying and editing huge delimiter separated files?

Perhaps you could tell us what you've already found and rejected?

If you've been searching, then you must surely have seen http://emacswiki.org/emacs/CsvMode ? You don't mention it, or say why it wasn't any good, though.

SES (Simple Emacs Spreadsheet) might be a useful approach:

C-hig (ses) RET

You can create a ses-mode buffer and yank tab-delimited data into it (that's the import mechanism).

It's probably more hassle than you were after, though, and I'm not sure how well it will perform with "huge" files.

Try csv-mode, which works in at least Emacs 24.

You can set the variable csv-separators to change the separator if you do not use the default one (comma).

See EmacsWiki.

There is pretty-column.el, which I found in Group gnu.emacs.sources years ago (it was added in 1999). That group is now blocked, by Google. I just used pretty-column.el on a ~5000 line tab-separated text file that Org mode choked on (Org mode has a 999 line limit on converting such a file--for that reason). Added in edit: This seems to now be called delim-col.el (see this Emacs Wiki entry); the author is the same person.