To join all of the letters together into one piece you will need to type each letter individually and use the outline function in XCS set to 0mm.

This will convert the text into vector shapes and allow you to edit and combine the letters into one shape. 

Once you have outlined all of the letters next you need to move them close enough together so that they are just slightly overlapping.

Then select all of the letters and use the combine unite function to make all the text into a single shape.

Now you should be ready to cut out the bookmark from your chosen materiel.

The settings provided here are for the D1 Pro 5w using 4mm MDF and may need to be adjusted for other lasers or materials.