In lists of entities such as the server browser with it's tables (or a table's specific constraints or indexes or triggers) or entities listed in the ER modeler such as the tables list, double clicking the item often expands it. Given that these items also have an expand/collapse caret, it seems like it would make more sense that double clicking an item would activate some other action-- such as edit table in the ER model or edit constraints, or opening up an Edit Table Data in the server/tables list.

In some cases it's clear what that double click should do (such as editing in the ER model). In cases such as the server/tables list, this action could be configurable-- such as choosing "Edit Table Data" or maybe a "Script Object to New Window as Select"