The Read a File action allows you to take the contents of a text or image file and put them on the system clipboard, a named clipboard or in a variable.
Click the File Chooser button to the right of the action to select an existing file on disk. Option-click on the File Chooser button to show the currently selected file in the Finder (assuming it exists already).
Select the destination from the pop-up:
If you select named clipboard then a pop-up allows you to choose which clipboard to write to.
Specify the variable to save the data to in the to variable text area, either by entering a variable name or choosing one from the arrow at the right-hand end of the text area.