Typically when you select all records it's because you want
to operate on those records immediately. The only case
this wouldn't be true is if you were scrolling, then selecting all
a bunch of times. I think it's more likely someone just wants to
select all, then delete.
Very useful final addition to the multi edit/delete function.
Typically a user will search for certain criteria, and then select
them all to be removed/edited. For example, if yesterdays sets were all
10x150kg deadlifts, but you review your form video and decide the form
sucked, you would want to mass edit them to lower the weight/reps (or
maybe delete them). This way you won't have these invalid entries
ruining all your progress graphs (showing false progress).