This is an UI issue that I found when testing Plone 5.0b3:
I added a table in a document using the TinyMCE. However, the UI have no default style alternatives via CSS clases as in Plone 4. Thus, after creating the table it is difficult to put data inside the cells, because no borders are visible and no padding is added. I now that I can change the table properties after creating the table. However, I prefer using classes instead of setting specific values and css commands for each table.
Thanks @keul , I'm going to put the issue there. I see that there are several issues that which titles start with "Plone 5:". However, there are another issues that are about Plone and do not use that prefix. Is there a policy on that?
I added the issue #755. However, I do not found the way of associate it to the Plone 5 milestone... Now I understand, it is a task to set the milestone. It have been filed into Plone 5.1.