New Data Entry User

In Data entry process, is there a way where I can select many rows in a column and put one value in a column.
Eg., My table has a column City and there are many rows. Can I select many rows and input "Ashburn" in the column City. Each cell has 15 cities from the list of cities (drop-down).
I hope I can get an answer here. I am learning SQL and this table was not created by me. I just input the data. Is there a way to make it faster?
Waiting a solution soon.