I can access my table through LibreOffice, but I can't insert or edit any data, it seems to be read only.
LibreOffice requires the table (or, more generally, data in a database) to contain a primary key to allow data editing. Some drivers, on a table that has no primary key but has a unique index, will advertise a unique index as primary key, which means that LibreOffice will allow data editing.
Alternatively, it is enough that the driver supports bookmarks [that doesn't sound right] (as certain ODBC drivers do, or the basic dBase implementation).
The reason for this requirement is that it is the only certain way to ensure that your changes are recorded correctly (in the case of editing) in order to be able to work on your new data later.