How to prevent table moving to the next page in Pages?
A table in Pages inherits its page break settings from the line on which it is located. (You can imagine the table is a huge character on a line).

To change the behavior of that line place the cursor at the end of the line above the table and press arrow right, moving the cursor to the table row. (Sometimes you'll see a blinking cursor along the left side of the table).

Now, choose Text formatting and click "More" and set up your paginations and breaks to your liking.

This way you can change the behavior of each table to break across lines or not as you see fit, and you don't have to change the behavior of all other text to do it...