Copy the code at the link below and paste it into a general module:

https://www.excelforum.com/showthread.php?p=3096647

Then, assuming this is your data:

Data Range
A
1
2
Cooperation
3
Curriculum Linked Activities
4
Familiarisation
5
Fun
6
Personal Challenge
7
Personal Development
8
Personal State Management
9
PSE
10
Self Belief
11
Skill Acquisition
12
Support
13
Training Course
14
#N/A
15
#N/A
16
#N/A
17
#N/A
18
#N/A
19
#N/A
20
#N/A
21
#N/A
22
#N/A
23
#N/A


Enter this array formula** in C2:

=concatall(IF(ISTEXT(A2:A23),A2:A23,""),", ")

** array formulas need to be entered using the key
combination of CTRL,SHIFT,ENTER (not just ENTER).
Hold down both the CTRL key and the SHIFT key
then hit ENTER.