Python 2, (削除) 370 (削除ここまで) (削除) 369 (削除ここまで) 368 bytes

Thanks to @sanchises and @edc65 for saving me a byte each.

J=''.join
u=raw_input().replace('\t',' \t ')
w=u[:]
G=range(len(u))
d,r=0,[[' 'for _ in G]for _ in G]
u=u.split('\n')
for t in G:
 x,y=0,0+t
 for c in u[t]:
 if c=='\t':d=(d+1)%4
 if c!='\t':
 if c.strip():r[y][x]=c
 if d<1:x+=1
 if d==1:y+=1
 if d==2:x-=1
 if d>2:y-=1
r=r[:max(i for i,n in enumerate(r)if J(n).strip())+1]
for i in r:print J(i).rstrip()

It generates the largest grid possible and then loops around, character by character, switching direction at each tab.

Python 2, (削除) 370 (削除ここまで) (削除) 369 (削除ここまで) 368 bytes

Thanks to @sanchises and @edc65 for saving me a byte each.

J=''.join
u=raw_input().replace('\t',' \t ')
w=u[:]
G=range(len(u))
d,r=0,[[' 'for _ in G]for _ in G]
u=u.split('\n')
for t in G:
 x,y=0,0+t
 for c in u[t]:
 if c=='\t':d=(d+1)%4
 if c!='\t':
 if c.strip():r[y][x]=c
 if d<1:x+=1
 if d==1:y+=1
 if d==2:x-=1
 if d>2:y-=1
r=r[:max(i for i,n in enumerate(r)if J(n).strip())+1]
for i in r:print J(i).rstrip()

It generates the largest grid possible and then loops around, character by character, switching direction at each tab.

Python 2, (削除) 370 (削除ここまで) 369 bytes

J=''.join
u=raw_input().replace('\t',' \t ')
w=u[:]
G=range(len(u))
d,r=0,[[' 'for _ in G]for _ in G]
u=u.split('\n')
for t in G:
 x,y=0,0+t
 for c in u[t]:
 if c=='\t':d=(d+1)%4
 if c!='\t':
 if c.strip():r[y][x]=c
 if d==0:x+=1
 if d==1:y+=1
 if d==2:x-=1
 if d>2:y-=1
r=r[:max(i for i,n in enumerate(r)if J(n).strip())+1]
for i in r:print J(i).rstrip()

It generates the largest grid possible and then loops around, character by character, switching direction at each tab.

Python 2, (削除) 370 (削除ここまで) (削除) 369 (削除ここまで) 368 bytes

Thanks to @sanchises and @edc65 for saving me a byte each.

J=''.join
u=raw_input().replace('\t',' \t ')
w=u[:]
G=range(len(u))
d,r=0,[[' 'for _ in G]for _ in G]
u=u.split('\n')
for t in G:
 x,y=0,0+t
 for c in u[t]:
 if c=='\t':d=(d+1)%4
 if c!='\t':
 if c.strip():r[y][x]=c
 if d<1:x+=1
 if d==1:y+=1
 if d==2:x-=1
 if d>2:y-=1
r=r[:max(i for i,n in enumerate(r)if J(n).strip())+1]
for i in r:print J(i).rstrip()

It generates the largest grid possible and then loops around, character by character, switching direction at each tab.

Python 2, 370 bytes

J=''.join
u=raw_input().replace('\t',' \t ')
w=u[:]
G=range(len(u))
d,r=0,[[' 'for _ in G]for _ in G]
u=u.split('\n')
for t in G:
 x,y=0,0+t
 for c in u[t]:
 if c=='\t':d=(d+1)%4
 if c!='\t':
 if c.strip():r[y][x]=c
 if d==0:x+=1
 if d==1:y+=1
 if d==2:x-=1
 if d==3:y-=1
r=r[:max(i for i,n in enumerate(r)if J(n).strip())+1]
for i in r:print J(i).rstrip()

It generates the largest grid possible and then loops around, character by character, switching direction at each tab.

Python 2, (削除) 370 (削除ここまで) 369 bytes

J=''.join
u=raw_input().replace('\t',' \t ')
w=u[:]
G=range(len(u))
d,r=0,[[' 'for _ in G]for _ in G]
u=u.split('\n')
for t in G:
 x,y=0,0+t
 for c in u[t]:
 if c=='\t':d=(d+1)%4
 if c!='\t':
 if c.strip():r[y][x]=c
 if d==0:x+=1
 if d==1:y+=1
 if d==2:x-=1
 if d>2:y-=1
r=r[:max(i for i,n in enumerate(r)if J(n).strip())+1]
for i in r:print J(i).rstrip()

It generates the largest grid possible and then loops around, character by character, switching direction at each tab.