define ndblock {
box wid boxwid/2 ht boxht/2
down; box same with .t at bottom of last box; 
box same
}
boxht = .2; boxwid = .3; circlerad = .3; dx = 0.05
down; box; box; box; box ht 3*boxht "." "." "."
L: box; box; box invis wid 2*boxwid "hashtab:" with .e at 1st box .w
right
Start: box wid .5 with .sw at 1st box.ne + (.4,.2) "..."
N1: box wid .2 "n1"; D1: box wid .3 "d1"
N3: box wid .4 "n3"; D3: box wid .3 "d3"
box wid .4 "..."
N2: box wid .5 "n2"; D2: box wid .2 "d2"
arrow right from 2nd box
ndblock
spline -> right .2 from 3rd last box then to N1.sw + (dx,0)
spline -> right .3 from 2nd last box then to D1.sw + (dx,0)
arrow right from last box
ndblock
spline -> right .2 from 3rd last box to N2.sw-(dx,.2) to N2.sw+(dx,0)
spline -> right .3 from 2nd last box to D2.sw-(dx,.2) to D2.sw+(dx,0)
arrow right 2*linewid from L
ndblock
spline -> right .2 from 3rd last box to N3.sw + (dx,0)
spline -> right .3 from 2nd last box to D3.sw + (dx,0)
circlerad = .3
circle invis "ndblock" at last box.e + (1.2,.2)
arrow dashed from last circle.w to last box chop 0 chop .3
box invis wid 2*boxwid "ndtable:" with .e at Start.w