GroupBy Table

I've no idea how to even start this, so I need help :-S

I have a table consisting of several columns, and the first 3 I want to group by and merge the rows if the content above is the same. I can loop through all the rows of the table and test the row above but if the group of rows is 3 or 4 I don't know how to detect and move to the row above.

For example, if I have a table like:-
What I need is to format it to:-Then to add insult to injury, I need to be able to search, which Ive done before by filtering through and hiding and showing rows with the data in, but once I start to merge rows Ive no idea how I can do this.

Can anyone help me with trying to figure out where to start on this issue, as I dont even know where to start on this

Thank you in advance