This is the variant with a 10 A rated current at 24 V, making it suitable for pilot-duty loads like PLC inputs, relay coils, and indicator lamps.
The 10 A at 230 V rating covers standard 230 VAC control circuits; at 400 V it still carries 3 A, enough for smaller contactor coils or solenoid valves on a 400 V line. The mechanical life of 30,000,000 operations means it will outlast most machines it's installed in — the contacts, not the mechanism, are the wear item.
That side clearance is tighter than some, so watch for adjacent components when packing rows. Terminals accept 2x (0.5 to 4 mm²) solid or stranded wire — fine for standard control wiring up to 4 mm². The standing mounting position is specified; if you lay it on its side, derating may apply (not covered here, but worth noting for the panel builder).