Once I choose "Accept quote" does this mean I am awarding the job to this one vendor?

Not at all. You can select as many quotes as you need to implement the project. It is possible to select all necessary quotes at once and save changes or select quotes and save changes on a step by step basis. Once you select a service provider’s quote and save changes you will see a note on a selected quote like "This quote was accepted". Upon quote acceptance a notification will be sent to a service provider. After accepting quotes you might wish to discuss project details with service providers.

Note: A job will not be closed once you select a quote(s). It can be closed by you manually (if you want so) or it will be closed automatically due to expiration of its quoting deadline time.