There are different companies, they pay for participating in online surveys, like serveysavvy, ejobsjunction.com, like wise. While participating in surveys, they ask for personal details, like age, income, profession etc. Is it safe to give such details?

Depends on how much you trust the site, but In my opinion, you'd be extremely naïve to give out too much personal information online.
Often these Survey sites are simply data miners and use the information for various nefarious acts and never payout what they say they will.
Best Avoided.