Assuming it’s a vaguely recent one set up by a vaguely competent company, you should need to get them to remove it from whatever device management service it’s attached to.

Ipad or Android tablet? If it’s Android look up how to reset using recovery mode (model of tablet). Generally it’s hold the home button, power button and volume down/up depending on model to turn it on and you can factory reset from there. Might not work depending on how it was set up as a “work” tablet but worth a try. If that doesn’t work and it’s still managed by your work when you reset it then you’d have to use a custom rom.

Probably has an MDM on it. You’re best option is to contact whatever IT people were in charge of the tablets and either ask them to remove the MDM or ask if they want it back.

You might be able to jailbreak it, there’s a lot of articles that say it’s legal and a lot that say it’s illegal. I wouldn’t recommend jail breaking anything unless you actually know what you’re doing and it makes any account on that device susceptible to malware. If you have any information like customer info or company info I’d probably not even consider jailbreaking it. I’m also not to knowledgeable on jailbreaking so maybe someone else can chime in.

If it were me I’d just try my best to contact their IT people with email and with calling. If no one answers and you don’t get a response back within a month I’d just sell it for parts after doing a factory reset if the MDM allows you to. Just make sure you have a lot of evidence that you attempted to return it.