Is it possible to create 100+ tasker profiles from a spreadsheet?
Tasker imports/exports are usually in XML format. You can export your Excel file to XML, but it'll need a lot of formatting to become tasker-readable. The template is listed on the sidebar for r/TaskerFiles/.

If you have the DOB in the correct field in Contacts, you can trigger a task off your calendar (in Beginner Mode / Tasker version 4.5u1m for Android 4+ : Create a profile with State > App > Calendar Entry). You can select a specific calendar, and there's a calendar that just contains the birthdays of your contacts.

That's the trigger. After that, you'd need to retrieve the name of the contact (which should be contained in the calendar event title), match it to a phone number, and then disable the trigger so you aren't sending SMSs all day while it's someone's birthday.