If your whole table will fit on one page, but is being pushed onto the next page due to previous content (e.g. in a situation where the table starts half-way down the page), you may be tempted to insert a manual page-break before the table so it starts at the top of the next page.
However, this will also add a blank line at the top of the page, above the table, and there doesn't seem to be a good way to get rid of this (aside from setting it to 1pt font, with no paragraph spacing, which is an ugly hack and somewhat fiddly).
An alternative approach that inserts a break without any additional whitespace is to select the first row of the table. Then click Paragraph Properties from the toolbar and tick 'Page Break Before'. This will force the table to the top of the next page without any additional white-space.
This won't solve the issue if your table is too big for a single page (scaling-down font sizes and other similar attributes is probably the only choice there) and it may need reverting if subsequent edits free up enough space to remove the need for a page break, but it is a good solution for some situations.