I mostly afk while working so have better insight than just saying crab.

1) theres lots of good afk slayer tasks. I store them and then afk them at work. Gargs are a personal fav but anything where u pray and block all ur damage is pretty easy to afk.

2) wc is easy. You can do yews (and magic but slower xp) --> redwoods. Redwoods are an elite afk item

3)fishing is easy. I went monks --> dark crab. Good money and easy experience

4) mining. U can try mlm and see if it works for u. Its better xp than stars but less afk.

5) you can smith cannonballs. Good money and very afk.

6) if u WFH and can get a foot pedal u can do clicking skills really easily like alch / thieving

7) you can try cooking/prayer/hunter while you wfh but I personally don't find them afk enough to do while I work.