(I ask Allah for forgiveness. (O Allah, You are As-Salam and from You is all peace, blessed are You, O Possessor of majesty and honour.) (AS-Salam: The One Who is free from all defects and deficiencies.))
Translated from Ustadz Firanda Andirja's Indonesian commentary (Bekal Islam). Quoted verses, hadith and duas keep their Arabic; where the commentary gave its own Indonesian rendering of them, that rendering is not translated and is marked [translation not shown].
This dua contains istighfar and praise of Allah by mentioning His beautiful names, namely "As-Salaam", as explained by Abu Umar Yusuf bin Abdillah Al-Qurthubi: As-Salam is one of the names of Allah, and it means the One who is free from every defect and deficiency.
(wa minkas salaam) as-salaam here means safety; that is, [translation not shown]. When a servant knows that no one can bring safety from every danger except Allah, and is also certain that safety comes only from Allah, this makes him hope for and ask for safety from Allah alone and from no one else. This is one of the values of tawhid in this dua.
(tabaarokta) is taken from the word al-barokah, which means the abundance and vastness of Your goodness, and it has already been discussed under the opening supplication (istiftah).
(yaa dzal jalaali wal ikrom [translation not shown]) Its meaning is as explained by Al-Qurthubi: its meaning is "that Allah is the Being who deserves to be magnified and honoured and not denied". This is because Allah alone is the most majestic and most noble Being, whose majesty and nobility cannot be denied. This is if we take al-Ikrom ("honouring") to mean the servant's honouring of Allah. It is also possible for al-Ikroom to mean Allah's honouring of His servants, that is, Allah honours His prophets, His awliya' (allies), and the righteous.