Remember webform textfield for next entry
This is the use case of the Webform Field Repeat module:


  The Webform Field Repeat module enables the webform to remember
  selected field entries from current submission for up to an hour. It
  uses the $_SESSION to do so. If the session is active, the form will
  be populated with selected entries from remembered submission when
  opened again.
  
  The fields can be selected on Webform >> Form settings for each
  individual webform. Once the fields has been selected the end users
  will see a check box at the bottom of the form that they can check to
  have the form populated when they open the form for a new submission.
  This module depends on Webform module.