Unless the job requires it, or the position would benefit from not being afraid to make a speech, I don't see how it helps.
HR won't care. They only look at the key words on the resume to see if you pass the first hurdle. They also reject those that far exceed the requirements for the job. If the job requires 5 years of X and you have 7, great. If you can play 12 musical instruments they won't care.
The people focused on picking the right candidate won't care about the extras listed on the resume, unless it directly applies. If you include outside activities and somebody making the decision likes that activity or appreciate that activity it can help them remember you. Otherwise it is neutral at best.
If during the interview they ask you for an example where you took the initiative on your own to improve your performance in the workplace: and you talk about how you felt your ability to talk in front of groups was poor, so you joined Toastmasters and now you are much better. That would help. But Toastmasters doesn't have to be on the resume, CV or cover letter to talk about it.