Yes, just separate the email addresses with commas.

Are you referring to E-mail Trigger?
I think I am good with that.
But, I am trying to email when survey is first mailed.
Is it possible? Sorry if this is duplicate question, but somebody mentioned that it is possible so I am little bit confused

Yes, I was referring to E-mail Triggers.
You can't send a survey invitation to more than one person.

Thank you for your answer!
My next question/challenge is, "is there a way to trigger an email when survey email is sent?"
I am trying to understand how I should go about doing this from bottom thread that @rondev answered on 5/9:
https://www.qualtrics.com/community/discussion/9873/how-to-cc-manager-using-contact-list#latest
But yes, if you want a setup wherein you want the email trigger should go to the respondent as well as their manager, then in the contact list you can create a column called managerEmail. Create a ED with same name in the survey. Now either in email trigger or email action, just pipe in this ED(managerEmail) along with respondent email in the "To" textbox, comma separated.
There seems to be only one option (Send An Email On Survey Complete) in Email Trigger.

https://community.qualtrics.com/XMcommunity/discussion/comment/25306#Comment_25306We really need to be able to send invitations to more than one person. Please pressure Qualtrics to do this!

https://community.qualtrics.com/XMcommunity/discussion/comment/41245#Comment_41245You should look to see if the product idea has already been submitted, and if so vote for it. Otherwise, you should submit the idea yourself.