This question raised when we worked at the client's side by one of developers. They use SQL Server 2005 (SP2) and remembered that in SQL Server 2000 we can open the table via EM and then specify (All rows , Top rows...) do you remember?
I rarely use SSMS to open/edit tables data, and it seems that MS just removed this option. In SQL Server 2005 we have TABLESAMPLE clause that used to open a table with lots of rows. So we only needed to see what kind of data this psecific table has without open entire table or using TOP clause.
This example returns an approximate percentage of rows and generates a random value for each physical 8-KB page in the table.
SELECT * FROM table
TABLESAMPLE system(5 PERCENT)
I'd really advise you to read BOL about this great feature