I can see how to do such a 2 row matrix, but what about extra rows?
Edit your question (don’t use an answer) to improve the description of what you try to obtain, e.g. give a text equivalent (caution: to keep a line break in the resulting question, ensure an empty blank line between rows).
Do you want to achieve this with Writer alone? Is this a “formula” Insert>Object>Formula formatted with Math?
Don’t forget to mention LO version and OS.