With the history browser you can browse through all the queries you have previously issued. To expand a given day's queries, double click on the day. To load a history item into the query area, double click on it or drag it to the query area.
You can remove history items by right clicking on them and choosing the Delete Selected History Entries option from the drop-down menu. You can also use the Clear History option to erase all history entries.
You can create bookmarks from history items by right clicking on a selected history item and choosing the Add History Item as Bookmark menu option.