In some cases, you will have a page with more than one table, and each will have some extra data that is related to it but isn't actually inside it, and can be marked as one or more fields.
In order to convert the data correctly from such a document, you can attach a field to a table by right clicking on it and selecting In Conversion, Show Field: With Table. The conversion will be the same as converting the field with Every Line setting, but it will only be added to the assigned table, not to all the tables on the page.
A field that is set to appear with a table will appear in each line of that table. If the field is then given a name, this name will appear as the header for the column that contains the field's value.
If you have several tables, which you convert as one big table by giving them the same table title, then names that will be used for the column headers for the fields will be the names of the fields attached to the first table. Changing the names of the fields attached to the other tables will not affect the output.
When you associate a field with a table in this manner, and the table is set to use the Find Table By Header option, then in each page the fields will only be visible if the table is found, and they will be moved together with the table if it isn't in the same position as the first page.
For an example of how and when you should use this feature, click here.