Hook: Floor Medium (Blue Square)The Arrangement: Cafe Table decoration fits into a blue medium square floor hook.
Hook: Floor Large (Purple Square)The Arrangement: Cafe Table decoration fits into a large purple square floor hook.
How to Get an Arrangement: Cafe Table Decoration
Cartel Pack Decorations
The Arrangement: Cafe Table decoration can be dropped from Architect's Stronghold Packs, which were released on the Cartel Market and bought with Cartel Coins. Cartel Packs, including the Architect's Stronghold Pack, include a random selection of items from the Architect's Stronghold collection of items. You aren't guaranteed to get an Arrangement: Cafe Table decoration from a Architect's Stronghold Pack, but it is one of the few ways to get an Arrangement: Cafe Table deco apart from buying it on the GTN from another player.
If you're looking to get a Arrangement: Cafe Table, 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. If it's very rare and not available on the Cartel Market, you could try buying from the GTN and hope you get it.