I think that depends on what kind of character you build. A trading/industrial focused character would need to do a lot of mining at first and that's basically just sitting around for ages waiting for your cargo hold to fill and it's something you can do while multitasking, though you have to keep an eye out for pirates (it becomes more fun later when you have better ships and better tools). There are also various missions where you fight NPCs or perform other tasks, like retrieving objects or performing courier missions. Some of the missions can take a few hours and if you take too long, they reset and more NPCs are sent.

I think there's probably less grinding for a fighter than for a merchant/manufacturer. You really can't avoid mining for the latter two professions.