It will depend on the type of finish that you want to have at the end and the present condition of the table top. It could be as simple as scuffing with fine steel wool, cleaning with alcohol, and applying a new finish all the way to completely removing the current finish with a ton of repairs. Pictures and specifics would help you get the best answers to your question.
https://www.youtube.com/watch?v=vjbJramreDg
https://www.youtube.com/watch?v=EQ_t5kLFGNs
Here is how I refinished this buffet top without stripping it. You may try the same technique. https://youtu.be/nslbSjKR2BE
It will depend on the type of finish that you want to have at the end and the present condition of the table top. It could be as simple as scuffing with fine steel wool, cleaning with alcohol, and applying a new finish all the way to completely removing the current finish with a ton of repairs. Pictures and specifics would help you get the best answers to your question.
I have a tutorial for you on refinishing and staining wood, if that's what you had in mind... https://www.youtube.com/watch?v=Grmaqgb1cbY&t=0s&list=PLhHahKs5Y6UlKfutKv6r0mc-Bqa5UOIVP&index=4