There is a table of contents in a hearing bundle, conventionally located at the start, listing every section, and every document within each section, in the order they appear, with page numbers, and there should be a corresponding PDF bookmark for every entry.
Whilst some practice directions issued by some specialist tribunals refer to this table of contents as exactly that, most practice directions issued by courts and other tribunals refer to the table of contents as the Index. Why is it called an Index when it is actually a table of contents? The word Index actually has a number of meanings. As well as the usual everyday meaning of an alphabetic index, Index is actually an old word for a table of contents. Index can also refer to a list.
The production of a hearing bundle is a collaborative task but one party has primary responsibility and starts off by sending the first draft of the bundle as a PDF to the other side. Hardcopies of the bundle may in due course be printed, but it is prepared and agreed first in PDF form.
However, in the past, before the use of computers became widespread, the bundle-producing party produced the bundle in paper form only. Because production of the full bundle in paper form was a labour-intensive task, the bundle-producing party initially sent the other party only a draft index - not a complete bundle. That index, as modified, eventually became the table of contents of the bundle when the full bundle was produced, but to call the initial index a draft table of contents might not seem quite right when as yet there are no "contents", and draft table of proposed contents is something of a mouthful. But since Index can mean "list", as well as "table of contents", index seemed the most appropriate choice of word.
The information above is necessarily of a general nature and will not be applicable to every case: it is intended to be used in conjunction with more specific advice to the individual client about the individual case. Contact me for advice about your case.