Botton with multiple text entries and a list option that adds data to bottom of table

I would like to create a button with two text and a drop down option that automatically adds data to the bottom of a table. I want the student name and group to be a text entry but I want the student grade to be taken from a list. As you can see in the sheet, I did the data validation route but I would like for the table to be infinite. I think a button would look better so that people won't have to keep scrolling down in the future. This is a sample data and the actual data has hundreds of students. I'd appreciate any help with this. Thanks.