Ah, finally, the explanation as to why he talked that way…
I remember drinking Tab to fit in with all the other figure conscious 11 year olds (how said a sentence is that?). We all know it was wretched but we choked it down anyway. When diet Coke came along it tasted like heaven in comparison. I can’t believe Tab lasted as long as it did but RIP [Rest In Putridness].
I used to drink it all the time when I was a teenager. I’m now a Diet Coke drinker. I don’t remember what Tab tastes like. I should have one for old time’s sake.
Dang, I’ve never had a Tab my entire life, and now, I never will.
You dodged a bullet. It’s like missing out on eating this.
I don’t even like Diet Coke - hate it, actually. I’m a Coke Zero guy. But Diet Coke was ambrosia next to Tab. Its most practical use might have been for cleaning car battery terminals.
Oh, that would be much better with home made Hollandaise.
Drink Diet Coke. It has much the same flavor.
Tab was one of those things you keep taking bites or sips of, thinking, “Surely it doesn’t taste as bad as I think it does!”
Tab was what Truman Capote drank at cocktail parties. Seriously!
My understanding is that Diet Coke was not intended to be similar in taste to Coca-Cola; though it may well have been based on the Tab formula, I’ve read that the taste profile which the formulators were looking to emulate was that of Diet Pepsi (which was, at that time, the leading diet soda).
Conversely, Coke Zero (which was introduced decades later) was intentionally formulated to more closely capture the taste profile of Coca-Cola.
Why do we(you) know this? I like it and will never forget it, but why is this known? How?
Glad you asked. It’s mentioned in this book:
And a good book it is, too! 
The ultimate 1970’s diet: Tab and Ayds candy. Now both are gone!
At least Tab was better than chocolate-flavored Diet Shasta soda - that stuff was nasty! The only other decent choice was Fresca, but it too had the weird saccharin aftertaste.
I remember my dad saying, “It’s probably called TAB because it tastes like a tab.”
A tab of what, IDK, but probably paper or some other non-food substance.
Back then, soda cans had pull-tabs, so maybe that was it. 
https://westerndigs.org/wp-content/uploads/2015/04/Beverage_pull_tab-featured.jpg
I concurs with kenobi that he likely meant the tab on the pop can. We still call them that, but they are now like this:
I think I once tried it when I was maybe five, hated it and never tried it again. Coke made Tab for a very small and vocal group of fans, probably also because of nostalgia that it launched a very successful drink genre. Coke Zero is basically my fifth food group.
Now what am I going to drink when I have a cough?