How do I copy a spreadsheet/table from one Pages document to paste to another?

Hello:

I am in graduate school and am working on an assignment that requires that I use two different 'templates,' or tables, to analyze data. Instead of filling them in separately and saving as multiple documents, I have created an assignment document with my header. I want to copy the tables from the two 'template' documents and paste them both to my assignment document. I've tried highlighting the table in the template document, clicking copy, and then pasting in my assignment document. Nothing is pasted.

What am I doing wrong?