[@Necroes] Thing is that might be true for a capitol ship. And troop transport ships would of course have tanks.

But this ship in particular is a sloop, it doesn't have the massed cargo space of other navy vessels. And thus would not have entire tank companies.
I'd say it has no troops whatsoever apart from the boarding defence and the security force (which mostly are the same dudes anyway.)
So on a cruiser, sure, there might be a tank or two.
Troop transport, probs rows of tanks.
Scout sloop..... naaah.

As i said, probs a light scout vehicle one can send down in a lighter, nothing big.
After all, why bring loads of troops in the light scout vessel? It's not supposed to be doing large planetary assaults.

Why would there be tanks anyway? In the ships armoury? The ship crew don't need tanks. It's probably mostly rows upon rows of ironclaw shotguns. And some boarding armours, heavy front, little back. Perhaps some flak shields as well.

And some random junk, it's an imperial vessel after all. Probs a bunch of melta paste, a bunch of plasma torches, some heavy stubbers. Because heavy stubbers are everywhere. Perhaps an autocannon or two... well, at least one as proven IC.
Might even be a meltagun in there.
But mostly ironclaws, this is a scout sloop after all. Top priority on this ship is sensors and jump drive, boarding gear is probably mostly "meh, here's some leftovers" and then the crew loot or otherwise get hold of some random guns.

What you need the tank for?