By default, revision schedules use a variable height, so that the schedules can expand to accommodate all of the revisions for a sheet.
If needed, you can specify that a revision schedule has a fixed (user defined) height. On a sheet in a project, the schedule displays only the revisions that can fit in the allotted space. If the sheet refers to more revisions than can fit in the schedule, Revit shows the most recent revisions and omits the rest.
To specify a fixed height, modify the revision schedule in the title block family, and use the Height option of the Revision Properties dialog, as follows.
To define a fixed height for a revision schedule
The status bar displays Schedule Graphics : Schedule Graphics : Revision Schedule.
The bottom of the revision schedule displays a blue dot. Grid lines display to indicate the amount of space required for each row of revision information (assuming one line per revision row; in a sheet, long values wrap to the next line). In this mode, these grid lines display regardless of whether the revision schedule is set to display grid lines.
The blue dot indicates the bottom boundary of the revision schedule. If a sheet in a project has more revisions than can fit in this space, Revit omits the oldest revisions from the schedule.