Blue mail-like highlights instead of table cells

Someone knows a way to get highlighted text items kind of the same way as in mail? I would like them to behave just like rows in a table in terms of selectability, but no rows and columns.

Like in this image:

that can be done with an NSTokenField (in the interface builder ‘text’ palette below the NSTextFields). Unfortunately there still seems to be poor AppleScript access to this item. But the functionality you mentioned (drag & dropping tokens) is built in.
To access the token field’s contents you can address it as a text field (it’s super class) and set/read the tokens as list:

set m to (contents of text field "tf" of window "main") as list
set contents of text field "tf" of window "main" to {"Token 1", "Token 2", "Token 3"}