Spike Lee's latest ''joint,'' the love story Mo' Better Blues, opened on only 544 screens in its first week of release-compared with the usual 1,000 to 2,000 for most major summer movies. Still, it brought in more than $8,000 per screen, the highest average for the week, and wound up with $4.4 million in its first three days. According to industry analysts, audiences graded the film very highly. If business stays strong during the next few weeks, Mo' Better has a chance to surpass Do the Right Thing's $29 million gross. With $95 million in hand, Die Hard 2 will soon join Total Recall and Dick Tracy as the third summer movie to pass $100 million. And even though it has taken in nearly $35 million in three weeks, Arachnophobia is limping a bit more at the box office than Disney would like. WEEKEND TOP TEN GROSS WEEKS IN GROSS* TO DATE RELEASE

1 $10.80 GHOST $69.13 4 Paramount (1,766 screens) 2 $10.18 PRESUMED INNOCENT $28.39 2 Warner Bros. (1,380 screens) 3 $8.02 YOUNG GUNS II $11.82 1 20th Century Fox (1,770 screens) 4 $6.84 PROBLEM CHILD $22.14 2 Universal (1,768 screens) 5 $5.96 ARACHNOPHOBIA $34.18 3 Hollywood Pictures (2,005 screens) 6 $4.82 DIE HARD 2 $95.63 5 20th Century Fox (1,946 screens) 7 $4 39 MO'BETTER BLUES $4.39 1 Universal (544 screens) 8 $3.88 DUCK TALES: THE MOVIE $3.88 1 Walt Disney (1,549 screens) 9 $3.44 THE FRESHMAN $10.15 3 Tri-Star (1,044 screens) 10 $2.76 JUNGLE BOOK $31.77 4 Walt Disney (1,478 screens) *weekend of August 3-5 (all dollar figures in millions)