Laundry Folding Table How Do I Clean My White Folding Table?

How do I clean my white folding table? - laundry folding table

I am a teacher with a pair of white folding tables in my room. Students are classified on the table with pen, pencil and marker, and I can not clean. I tried bleach, kitchen cleaner, Windex (I'm desperate), and nothing worked. These are the Average White boards for picnic, conference rooms, laundry and use any use other misc. Any help is welcome. Thank you!