Apologies, I thought the split was a consequence of a table spanning several pages. In this case, the page is only spread over several physical pages without being interrupted.
The split operation you described is one of the numerous “convenience” operations provided by Writer to avoid recreating “objects”, like tables, from scratch. There is a fair amount of arbitrary choices in them. Style for the intermediate empty paragraph is one such choice.
But, Body Text is probably the most innocuous one as Body Text is intended to be the “normal” discourse style. Usually you customise Body Text instead of creating your own one. All these “convenience” behaviours rely on implicit (alas) assumptions like Body Text.
Unfortunately you can’t modify this behaviour. So, try to follow the assumptions. Shame is they are explicitly described in the documentation.
Concluding remark: congratulations for your use of styles. You have only one occurrence of direct formatting (in “Layout of charts” with Format
>Bullets & Numbering
). However, since it brings no number nor bullet, you could as well get rid of it. You can also improve the names of your styles: instead of describing their effect (bold, left/right, …) which locks you into this style state and prevents any consistent configuration change, hint at style usage like Body Text or Heading 1. This grants you total liberty in customising the style configuration while keeping the same usage.