How to delete unwanted default templates and categories?

As I asked. I makes me confused to see a lot of unwanted, default templates and template categories. Is is possible to switch them off? I work on:
Build ID: 92a7159f7e4af62137622921e809f8546db437e5
CPU threads: 8; OS: Mac OS X 10.11.6; UI render: domyślny;
Ustawienia regionalne: pl-PL (pl.UTF-8); Calc: group

Think you can delete category by choosing small arrow in template manager at bottom left. Can’t you select template and do right click on template and choose delete. I ask as I don’t have Mac so not sure if you just missed that or something is different then on my operating system.

Is this helpful?

Yes, I know the way, but it do not works for me.

You should mention that in your question (try to edit it) and also describe what happens when you do what I suggested in answer. Does deleted category reappear? Do you actually want stop template manager from showing at all rather then delete specific category or template from it?

See my answer below.

I had mandatory default categories and templates. Which I can not delete and they are annoying to see. My work around is to split mandatory templates:

vpn143:Resources pni$ pwd


vpn143:Resources pni$ ls -la

drwxr-xr-x@ 4 pni admin 136B 4 lis 16:24 officorr
drwxr-xr-x@ 3 pni admin 102B 4 lis 16:24 offimisc
drwxr-xr-x@ 4 pni admin 136B 4 lis 16:24 personal
drwxr-xr-x@ 15 pni admin 510B 21 sty 12:06 presnt
drwxr-xr-x@ 4 pni admin 136B 4 lis 16:24 styles
drwxr-xr-x@ 7 pni admin 238B 4 lis 16:24 wizard

vpn143:Resources pni$ ls -la

drwxr-xr-x@ 30 pni admin 1,0K 4 lis 16:24 bitmap

vpn143:Resources pni$ ls -laR template/

drwxr-xr-x@ 3 pni admin 102B 21 sty 12:35 common

drwxr-xr-x@ 4 pni admin 136B 4 lis 16:24 internal

-rw-r–r–@ 1 pni admin 5,4K 4 lis 16:24 html.stw
-rw-r–r–@ 1 pni admin 23K 4 lis 16:24 idxexample.odt