If the table really is "full page", from the top margin to the bottom margin, you cannot simply insert a paragraph before the table and expect both to remain on the same page.
There are two viable solutions: Either adjust the size of the page area by making the top and bottom margins smaller (and also adjusting the heights of the header and footer areas), or adjust the size of the table by reducing the font size of the table's contents.
Adjust the margins by clicking Layout > Margins > Custom Margins, and changing the values in the Top and Bottom boxes. If the Apply To box shows "Whole document" this will affect all pages. If you want to change the margins for just one page, manually insert section breaks before and after the table, click anywhere between the breaks, and set the Apply To box to "This section".
If you choose this method, also click the Layout tab in the dialog and change the header and footer "from edge" settings to values smaller than what you changed the margins to.
Adjust the table size by selecting the whole table and entering a value for the font size on the Home ribbon. If the minimum row height (in the Table Layout > Properties > Row dialog) isn't set, the row heights will adjust to fit the reduced font size.