Well,
Normalization is what you should learn to solve this problem.
The simple rule could be all those 30 fields directly dependent on the same primary key then just keep them in the same table. However, you can keep few information in another table based on their usability but most of the people will recomend to have a single table if the above condition is true in your case.
Please refer to below links-
Database Normalization[
^]
What is Normalization in SQL ? - SQLServerCentral[
^]
Hope, it helps :)