it opens a new tab in chromium, on the pi controlled touchscreen I have as a dashboard.
Is it any way of forcing it to open a new smaller browser window?
or is that a setting I need to to in chrmoium on the pi controlling the dashboard?
If by a smaller browser window you mean something like a popup, then have a look at the popup service of browser_mod.
You can have whole lovelace cards popup whenever you click on desired items.