The 5TT5830-0: The 230 V AC coil voltage is the control circuit voltage — that's what the PLC or switch feeds to pull the contactor in. The 400 V maximum across the main contacts means it can handle line-to-line voltages common in three-phase panels up to that level. The 2,000 W incandescent lamp load rating is a specific marker for lighting panels — if you're switching a bank of tungsten lamps, this contactor is sized for that inrush.
The evidence notes that spacers are required between adjacent units to ensure heat dissipation; don't pack them tight without the recommended air gap. Supplementary devices (auxiliary contact blocks, surge suppressors) can be added on the side or top, so you can build out the contactor's function without replacing it.