tatah sa vismayavisto
hrsta-roma dhananjayah
pranamya sirasa devam
kritanjalir abhasata

"Then, bewildered and astonished, his hair standing on end, Arjuna bowed his head to offer obeisances and with folded hands began to pray to the Supreme Lord."

It also looks like what Sanjaya saw and narrating to Dridarashtra. Till sloka 13, Sanjaya told what he saw as Viswaroopam. This sloka mentions that Arjuna prostrated to the Lord in Viswaroopam. From sloka 15 to sloka 51, a perplexed Arjuna praises the Lord. This Chapter is almost the praising words of Arjuna. In the First Four slokas Arjuna expressed his desire to see Viswaroopam. In the next Four slokas, Sri Krishna told Arjuna that He would equip Arjuna with divine eyes to view Viswaroopam. In the next Five slokas, Sanjaya narrates the Viswaroopam he was able to see. In this sloka, Arjuna is astonished to see the Viswaroopam and feels goosebumps on his body [hair raising emotion] and prostrates in reverence to the Lord. Then he starts speeaking. Tata = then or after seeing the Viswaroopam, sa dhananjaya = that Dhananjaya [Arjuna]. Dhananjaya means amassing wealth after victory. Earlier he was Dhananjaya only in name, but now after seeing Viswaroopam, Arjuna is real Dhananjaya. By seeing the Lord in His True form, Arjuna had acquired the greatest wealth. Swami Alavandar says that the Divine feet of the Lord was his wealth. Swami Desika in his Vairgya Panchakam says that the wealth, we try to acquire in our life by praising and serving mortals, so as to quench the ever demanding hunger in our stomach, is useless. Real wealth is only the Lord. Vismayavista = wonder struck or astonished, hrsta-roma = hair raised [goosebumps] [மயிர் கூச்செறிதல்]. Arjuna was wonder struck and in emotion his hair all over the body raised. Pranamya = falling flat or prostrating, sirasa = with head on the ground [ as a mark of respect to], devam = the Lord, in Viswaroopam. Whenever we see great people or we see the Lord, we have to prostrate by falling at their feet as a mark of respect. When we prostrate eight things have to touch the ground or have to fall - Two arms, two legs, one head, intellect, mind and ego [ahankaram]. Thus Arjuna was so much surprised to see Viswaroopam, that he fell down to show his respect. Devam means brilliant, and also playful. Playful, because Arjuna wanted to run away from the battle and was confused, and now He stands in total admiartion of the Lord's creation. Kritanjali = with folded hands, abhasata = [Arjuna] started to speak. Arjuna saw Viswaroopam and awed, emotion made his hair to raise and he fell down with head touching ground, in respect. Then he got up and with folded hands, as we say namaste or namaskaram, he started speaking. What made Ajuna to wonder? We have seen supporting objects. But the object and the supporter are totally separate and can exist independently. But here, the Lord supports by being their antaratman or the inner soul, and at the same time he was able to see all those objects on His body. Everything is His body and is able to command, control and sustain. This is something Arjuna had never heard of and so he was perplexed. We will now take leave of this Kshetram.