Typically this would be architected in a different way.
Maybe you send the form to each user but then they only see their tasks. This allows one distribution but then it is smart and identifies the user and shows them what they need.
Another would be to email a link and then again the form shows them their tasks and maybe they mark them done or have other communication and workflow.
Or if you have Sharepoint you could post these tasks to a list.
Or you create one form per assigned task.
Another option is to use the Database Accelerator, save the task data to SQL and then have SQL trigger an email to each user based on the data as it is saved to the table.
If you want to send an email for each task they have then within one form then I would probably recommend using a code based or command line SMTP client which could bulk mail these simple emails out. Otherwise the person making the assignments would have to manually send each one anyway. Otherwise you would need to loop through and each time change the parameters for the email and ten submit again. The user would press send and then the next would popup.
I know there are some threads here on using code based email.
Good luck.