Patrick,
There are no tabs in (99%) PDF files. This are so many ways to draw tabbed text in to a PDF while which makes it impossible to reliably convert text to columns.
Most text in a PDF file is drawn using either
MoveTo(x, y); DrawText("Hello"); MoveTo(x1, t1); DrawText("Hello World");
Some PDF will draw each character individually this way. Others will draw "Hello W" and "orld" as two separate words. Characters can have character spacing and word spacing values applied as well as scaling, rotation etc. I have seen all sorts of ways of drawing text which is why you need a solid PDF to Text library to get the best results. Proportianal fonts will also cause you lots of issues.
ie. There is no quick way to get the columns from your text without writing some fancy code.
Andrew.