Hi Vinay,
first of all create a multipline container element on your task container of send email step. Then bind the data from workflow container to multiline task container (which needs to be displayed/send in an email).
in the task description editor of send mail, click on INSERT->EXPRESSION then select your multiline container element which you need to display. SAP will give different options (e.g. display lines in different lines).
Regards,
Ibrahim