I was expecting a table which would tell exactly how many points are earned and by what activity.
You can find such a table on the right hand side of the page at the following link,
Does the quality of answer also affects earning points? or it is just acceptance of answer?
Acceptance of your answer by others is sufficient to get points, but accepting your own answers will not earn you points.
Can more than one answers be accepted at once?
Not currently, but there are rumors that that feature may eventually be added. You can vote for multiple answers, though, except your own answers of course.
Does asking good questions also earn reputation?
People can vote for your question (as I've now done for you) and that will earn you 1 point per vote.
What is usefulness and significance of earning reputation (other than powers earned to edit, delete etc.)
That's it, for the most part. Some people posting questions might also look at your profile and use your reputation as a basis for how much they trust your answers, not that that's always a good thing...
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