Assign Multiple Values to a Single key tag In AWS

No - single tag, single value. However you might consider using (say) a comma or semicolon as a delimeter and then parsing the tag value. Note that you shouldn't do this for billing tags.

What do you need multiple tag values for?

Hello

You can't simply, Each key must have Uniq Name, But you can do another way for example

Name-1  Project1
Name-2 Project1
Name-3 Project1

You can have a tag with multiple value field of the tag. An example is mentioned in our documentation.

The example is with the tag 'team', where more than one team is associated to that resource.

team = Engineering:QA

The delimiter is ":", but could be other valid separators. Using this to control for access takes special consideration on how you craft your policy for those values.