Please note
You will have to have Author access to do this.
It's possible to let your students download an Excel document from the exercise, which they can then fill in, and upload next to their answer, or upload the Excel document as the answer to that exercise.
Adding an Excel document to the exercise
Go to the Author tab, and find your exercise.
Click on it to edit the exercise, and go to the General tab.
Under "Upload" click on Add files button.
Select the file you wish to make available to the students. The file types that are accepted are: pdf, xls, xlsx, doc, docx, ppt, pptx, odt, ods, csv and txt.
Don’t forget to press Start after the selection has been made, otherwise, the file will not upload.
It will look like this, when successfully uploaded:
Go to the text field you wish to insert the link. Go to Insert → Link, and select the uploaded file from the Link list dropdown menu. Click Ok to finish.
Can the Excel document be the student's answer to the question?
Yes, it's possible for students to answer the question by uploading the Excel document. This is done by creating a "file upload question type". Please see the article here on how you can create this type of question.
Can the students upload the Excel document next to their final answer?
It's possible to let students upload Excel files to the question. You can create an open-type question and then let students upload files in the general test settings. Please see the article here on how to let them do this.
If you do this, please note that it won't be possible to automatically grade this exercise.