[daptaq]

> and then you can just press "e" to repeat it again and again.

You can also pass C-x e a 0-prefix argument (M-0 C-x e) and it will repeat the macro until the bell rings, which usually happens when a movement command like forward-line, forward-sexp, etc. reaches the end of a buffer.

Another strategy is to record a macro that only operates on a single line, then mark the region you want to repeat it in for every line and then execute it on all these lines using C-x C-k r.