This happens because the generator simply puts one tab between every value in the row. This is the conventional way of writing tab separated values. It's done this way because the data is primarily intended to be ingested by computers, not really humans. The generator isn't trying to create a list that looks wonderful (but there is a hope that it's a little easier to eyeball than comma separated values).
How exactly are you reading the data? If you're just reading it right there on the website, why not save it to a file and open it with a spreadsheet viewer instead? Google Sheets is free, and so is LibreOffice if you're a little bit crazy. There's also the Pokedex with stats that has all but a few features of the generator.
(disclaimer: i didn't make the tool)