Aside from line memorization, voice acting work is pretty easy, y'know. Most shows, you can easily record an episode inside of a day's session. If you're not doing big parts on multiple shows, you're going to be doing lots of little parts to fill up the work week.
I mean, you cut out a lot of the more complex parts of acting. Regular acting is time consuming because between every take, you have to reset the set, check makeup, etc. With voice acting, you flip back a few pages of script and rewind the tape. You don't have to worry about the light going wrong or the weather ruining the shoot, effects going wrong, any of that.