The Imperial Crate Pallet deco is part of the Imperial Essentials Bundle, a set of decorations that you can buy directly from the Cartel Market with Cartel Coins. All decorations from the cartel market, including the Imperial Crate Pallet deco, can usually be found on the Galactic Trade Network (GTN) and bought from other players with credits.
If you're looking to get an Imperial Crate Pallet, the easiest way to get it is to head to the Galactic Trade Network (GTN) in SWTOR and buy it with credits from another player. You can also buy the full Imperial Essentials Bundle from the cartel market or GTN, which includes this deco and a few others that match.
Contributors: Thank you Solomon for allowing me to take screenshots of this decoration!