Concatenate row values into single cell

From Excel 2016 there is the TEXTJOIN function to do that. In Excel 2010 chances are that you will need a UDF, meaning VBA. But in either case the information you provide is insufficient.

Key to the deployment of any function is the size and nature of the range to be concatenated. Is it dynamic, meaning of varying size? It's a lot easier if the number of concatenations are always the same. If they are not you need to know how the range is defined.

In your example the range is column B but it's defined in column A. There is a word to mark its beginning and the end of the sheet to mark its end. But that's a hastily prepared example. In real life the conditions may be totally different. Post an example that resembles your real problem more precisely.

But first, decide whether you are going to upgrade to Excel 365 or agree to use VBA. Or, perhaps your range need not be dynamic in which case neither of these will be necessary.