The Trade Log window displays all the trading activity during the current CPT session - that is, since ChartPattern Trader was last started. It is cleared between sessions, so if CPT is stopped and then restarted, the log will be cleared.
Any trading activity that happens on an account that is "active" in CPT (meaning, its trading window has been brought up or it was used in Chart Trading) will be reflected in the Trade Log window.
For user convenience, the Trade Log window can be filtered by account, symbol, or activity type.