I have started a soffice text document and I see that some normal text (style: Text Body) appears in the TOC, while other text passages (style: Text Body) correctly do not show up in the TOC.
How can I ‘remove’ passages of normal text from the TOC?
You can “remove” a style from a passage by applying a different style or applying a direct formatting.
TOC has its own style. F11 and then look under paragraph styles for “Table fo Contents”.
I recommend to have a look at the free guides, which you can download from http://www.libreoffice.org/get-help/documentation/
If this is not the solution please re-phrase your question and explain all the steps you did and tried and the results. This enable a better understanding or simulation.