Formatting for Mail Merge

This may be a Microsoft Word mail merge problem. But I am thinking maybe I can set my Excel spreadsheet better. The problem I am having is that a teacher may have one student, or may have up to 30 students assigned to them. When I do the mail merge it will give me a new page for each student. So if a teacher has five students, I get five pages with each different student. How do I keep it on one page. The Excel spreadsheet has 500 rows of names with different teachers. I am attaching an example. Is it a Excel configuration or a Word configuration that I need. Thank you.

It may be possible to create one page(one tab for each teacher or student in excel. You should be to create single tab for each data in one of the columns, A,B or C. Is this what you are after?