It depends on the master, what job the slave held, and the time period you were a slave.
Unskilled slaves, or those sentenced to slavery as punishment, worked on farms, in mines, and at mills. Their living conditions were brutal, and their lives short. Skilled slaves, such as accountants or physicians were actually paid money and were allowed to own property. This allowed them to eventually buy their own freedom.^1 I would like to note that even if a slave owned property it was still considered to be owned by the master. The slave was allowed to use it how he pleased though. Afterwards the slave was able to take complete control of the property. "A notable example of a high-status slave was Tiro, the secretary of Cicero. Tiro was freed before his master's death, and was successful enough to retire on his own country estate, where he died at the age of 99"^2
There aren't that many cases recorded as to how slaves were treated, but notably "Cato the Elder was recorded as expelling his old or sick slaves from his house. Seneca held the view that a slave who was treated well would perform a better job than a poorly treated slave."^3
Over time slaves started to gain more rights. "Several emperors began to grant more rights to slaves as the empire grew. Claudius announced that if a slave was abandoned by his master, he became free. Nero granted slaves the right to complain against their masters in a court. And under Antoninus Pius, a master who killed a slave without just cause could be tried for homicide"^4 . About the time of stoicism's appearance "Legal protection of slaves continued to grow as the empire expanded. It became common throughout the mid to late 2nd century CE to allow slaves to complain of cruel or unfair treatment by their owners." ^5
Cicero, Ad familiares
Kehoe, Dennis P. (2011). "Law and Social Function in the Roman Empire". The Oxford Handbook of Social Relations in the Roman World. Oxford University Press. pp. 147–8.
Jane F. Gardner. 2011. "Slavery and Roman Law," in The Cambridge World History of Slavery. Cambridge University Press. vol. 1, p. 429
Dillon, Matthew and Garland, Lynda. Ancient Rome: From the Early Republic to the Assassination of Julius Caesar. Routledge, 2005. Pg 297
McGinn, Thomas. Prostitution, Sexuality, and the Law in Ancient Rome. Oxford University Press, 2003 Pg. 309