Why do ask?

The reason I ask that is because it was more possible to get a big number in the past than it is today. For example, it used to be that if you applied for card A today, the pull wouldn't show up on credit bureaus until tomorrow, so you could apply for card B a few minutes or hours later and know that it would not show the extra pull from card B. And repeat for card C, card D, etc. That was typically called an App-O-Rama (or AOR for short, but keep in mind that in other contexts AOR has other meanings, like a radio format!).

But these days pulls show up pretty instantly, so this trick is no longer possible. Thus there's no longer much advantage to applying for lots of cards in the same day.

Also, many banks that used to allow applying for multiple cards on the same day (and processing them on the same day) no longer do. So again for that reason, there's no longer much points in applying on the same day.

So if you just want it for historical curiosity, great, but if you want to know what's repeatable, only datapoints that are recent would help for that.

Search FT for "App-O-Rama" and/or "AOR" (you might need to put in quotes) and you'll find plenty of individual reports from the past.