The Firefox when you ask it to open a new tab, it shows you a list of top sites in your history. This list consists of 8 suggested websites placed in a row and is called Top Sites.
Η choice they are based on your history and are the websites you visit the most. You have the possibility to delete a selection of it Firefox but the next option of the browser automatically takes its place. You also have the ability to discard sites and effectively hide them from the Top Sites entry, as well as rearrange the top locations using drag and drop.
Since Top Sites are quite easy and convenient, let's see how you can increase the number of Firefox suggestions and a series of 8 tiles to make more rows.
First of all, it is quite easy to increase the number of rows to two, as the Mozilla added an option for this job. Doing click on the gear icon in a “New Tab” (top right) various options appear. Among them, find the “show two rows” option under “Top Sites”, check it and a second row will be added to “Top Sites” when you request a new tab.
However, if the two rows of top websites are not enough for you and you want more rows, Firefox gives you the option and you should take the following steps:
1. Open a new tab and copy-paste it to this address bar:
about: config?filter=browser.newtabpage.activity-stream.topSitesRows
2. On the page that appears, say "Take the risk", then double-click browser.newtabpage.activity-stream.topSitesRows and change the existing value to the number with the desired number of rows.
3. Click ok.
Now check out a new tab and you will see the change immediately and, if necessary, modify the number of lines according to your wishes. See below how our selection appears with 4 rows: