Strange argument, bro. These words come AFTER the supper is over (already ate the meal/lamb sop had concluded). Judas was there for the meal (obviously, Jesus handed the lamb sop to him) but is he there AFTER supper? Casual reading acts like he IS there because the statement includes "IS" (present tense). But, not one Greek document has the word "is" in the verse. The KJV accurately uses italics to show that "is" is a man-made addition to God's Word. When they were eating earlier, "is" would be correct. Now? All the other eyewitnesses (not Luke, second-hand information) say Judas LEFT.
If Jesus atoned for Judas' sin (atone = paid the penalty, covered, once-for-all deal), then Judas will be in heaven. A just God cannot demand payment twice if Jesus paid it all. Of course, that is absurd.
how about checking the Greek? the words, "of him that betrayeth", is from the Greek, παραδιδόντος, the verb is in the present tense, showing that Judas was WITH Jesus when He was speaking! Literal translation is, "the hand of he who is betraying me, is still with me at the table". That is why the KJV added "is", because it is what the Greek text says!
ESV, But behold, the hand of him who betrays me is with me on the table.
NASB, "But behold, the hand of the one betraying Me is with Mine on the table.
HCSB, But look, the hand of the one betraying Me is at the table with Me!
CEV, The one who will betray me is here at the table with me!
NIV, But the hand of him who is going to betray me is with mine on the table.
NLT, “But here at this table, sitting among us as a friend, is the man who will betray me.
NET, "But look, the hand of the one who betrays me is with me on the table.
NAS, “But behold, the hand of the one betraying Me is with Me on the table.
ASV, But behold, the hand of him that betrayeth me is with me on the table.
ERV, But behold, the hand of him that betrayeth me is with me on the table.
Weymouth, Yet the hand of him who is betraying me is at the table with me.
Webster, But behold, the hand of him that betrayeth me is with me on the table
Young, But, lo, the hand of him delivering me up is with me on the table
WEb, But behold, the hand of him who betrays me is with me on the table.