The most common use of a Moodle wiki is a sign-up sheet for your students.
How to create it?
1. Turn editing on > Add an activity and resource > Select Wiki
2. Fill in the name and description (do not copy the sheet in yet!)
4. Open the wiki and create the "first page" (HTML format)
5. Copy/Paste the sheet in to the box. Check the formatting - it is recommended to use an excel document with basic formatting, as coping from MS Word could result mild formatting errors.
How can students use it?
They just need to open the Wiki, and click on the "edit" tab > Edit/fill in data > and save.
Important note: only one student can edit a wiki at the same time.
If you would like to use a document with synchronous access to all students you may use Google documents and share it in Moodle (with a link).