SSRS - Show blank / Empty rows in Table

1.Insert a new rows in the table

2.Set the visibility using the following expression

=IIF(CountRows() < 1 = 0, true, false)

Note:
Similarly we can show multiple empty rows.
in my case ,i added 10 empty rows & set the row visibility using below expression

=IIF(CountRows() < 1 = 0, true, false) - first row
=IIF(CountRows() < 2 = 0, true, false) - 2nd row, etc..

SSRS - Forcing subreport Contains Empty data / no rows to Show

1.Add a dataset ("dataset2)" in sub report with following query

SELECT ' ' AS DUMMY

2.Add a empty textbox with following expression
=First(Fields!DUMMY.Value, "DataSet2")

Reference:

https://coderwall.com/p/meqrng/forcing-a-ssrs-subreport-to-show