These beeswax tablets could be of plain beeswax, or they were some times coloured black, green or red.
This wax tablet book is undated.
Late 17th century. The writing stylus for this wax tablet book is shown below.
Note the top of this stylus is shaped for smoothing the surface of the wax tablet, erasing previous writing.
This is an early 17th century German wax tablet leather case with tablets.
How to make wax tablets: http://www.randyasplund.com/pages/article/waxedtabletstylus.html