Yes. The procedure to change it is slightly different depending if it is a User Phone or a Room Phone. One thing to remember in either case is that the phone displays are not very big and any name longer than about 12 characters will be truncated on the display.
For a User Phone, the user can configure this by logging in at https://dialpad.com. Once you are at the Your Profile page, click Edit Personal Information. After you make the change it will take about 12-24 hours before your phone display is updated. To force it to update immediately, reboot your phone.
For a Room Phone, this can only be changed by an Office Admin. Login at https://dialpad.com, click Office Settings, and click Desk Phones, then Room Phones, then click Options next to the phone you want to change and choose Edit. Enter the new name at the top and then click Done. After you make the change it will take about 12-24 hours before your phone display is updated. To force it to update immediately, reboot your phone.