The Table Locator detects the start of a table using table header packs, a locator, or a start-of-table dictionary. Each of these start-of-table detection methods work in the same way. (The locator excludes all rows that precede the start of the table from the table line items.)
Although it is more difficult to add a table header pack than a locator or dictionary, it yields better results when detecting the start of a table.
If you use a table header pack as well as either the locator or dictionary methods to detect the start of a table, the table header pack always gets evaluated first. If a result is detected, the start-of-table dictionary or locator are never evaluated. If the table header pack cannot locate the start of a table, the dictionary or locator is evaluated.
The locator or dictionary provide alternative solutions for detecting the start of a table if the header pack fails for any reason. As a result, you should always use a table header pack and a dictionary or locator, if available, to ensure that the start of a table is detected.