cut down data sizes for pytables related vbenches
Those are really slowing down test perf

```
join_dataframe_index_single_key_bigger      9.5578    11.1325     0.8585
join_dataframe_integer_2key                 4.7822     5.4330     0.8802
panel_from_dict_all_different_indexes      71.4074    81.0831     0.8807
timeseries_add_irregular                   21.5136    24.1530     0.8907
panel_from_dict_equiv_indexes              25.8620    28.8970     0.8950
reindex_daterange_pad                       0.1732     0.1935     0.8950
read_csv_thou_vb                           33.3554    37.2321     0.8959
groupby_frame_singlekey_integer             2.1610     2.4077     0.8976
panel_from_dict_same_index                 25.8203    28.3975     0.9092
lib_fast_zip                                9.9503    10.7844     0.9227
groupby_multi_different_functions          12.3623    13.2350     0.9341
panel_from_dict_two_different_indexes      49.1490    52.6084     0.9342
frame_fillna_many_columns_pad              14.0718    15.0286     0.9363
stats_rolling_mean                          1.2735     1.3558     0.9393
stats_rank_average                         25.4836    27.0692     0.9414
series_align_int64_index                   37.9021    40.1850     0.9432
frame_drop_duplicates                      22.3100    23.5742     0.9464
dataframe_reindex_daterange                 0.4227     0.4461     0.9474
reindex_daterange_backfill                  0.1947     0.2049     0.9501
index_int64_union                          74.8751    78.6099     0.9525
frame_boolean_row_select                    0.2366     0.2470     0.9580
dti_reset_index_tz                         15.4665    16.1267     0.9591
merge_2intkey_sort                         40.6254    42.2835     0.9608
join_dataframe_index_multi                 21.5843    22.4350     0.9621
read_csv_comment2                          26.2610    27.2638     0.9632
write_store                                13.9323    14.4345     0.9652
timeseries_period_downsample_mean          10.2110    10.5601     0.9669
read_csv_vb                                27.0146    27.8807     0.9689
write_store_table_mixed                   991.7591  1022.1848     0.9702
stat_ops_level_series_sum                   2.0037     2.0612     0.9721
groupby_frame_apply_overhead               10.8793    11.1625     0.9746
frame_fillna_inplace                       11.9844    12.2915     0.9750
frame_iteritems_cached                      0.0742     0.0761     0.9752
read_store_mixed                           13.2591    13.5911     0.9756
frame_sort_index_by_columns                42.1859    43.2073     0.9764
stats_rank_average_int                     19.7597    20.1886     0.9788
groupby_frame_median                        5.5557     5.6732     0.9793
frame_ctor_list_of_dict                    72.5023    73.9728     0.9801
index_datetime_union                       12.6782    12.9208     0.9812
stat_ops_series_std                         0.6514     0.6632     0.9822
groupby_frame_cython_many_columns           2.7002     2.7479     0.9826
period_setitem                            843.1060   854.2030     0.9870
query_store_table_wide                     15.5194    15.7222     0.9871
stats_rank2d_axis1_average                 15.3458    15.5261     0.9884
sort_level_one                              3.7356     3.7692     0.9911
stats_rank2d_axis0_average                 26.0081    26.2205     0.9919
timeseries_asof                             9.7938     9.8685     0.9924
read_store_table_panel                   1493.6681  1504.2000     0.9930
stat_ops_level_frame_sum                    2.6737     2.6915     0.9934
series_drop_duplicates_string               0.5648     0.5678     0.9948
series_align_left_monotonic                17.5371    17.6139     0.9956
reindex_fillna_pad                          0.0782     0.0785     0.9963
frame_reindex_axis0                         1.1610     1.1606     1.0003
timeseries_slice_minutely                   0.0515     0.0515     1.0010
ctor_index_array_string                     0.0148     0.0148     1.0010
timeseries_1min_5min_mean                   0.6241     0.6231     1.0017
frame_reindex_axis1                         2.7216     2.7157     1.0022
join_dataframe_index_single_key_bigger     17.0331    16.9749     1.0034
frame_fancy_lookup                          2.1919     2.1755     1.0075
read_csv_standard                          12.7835    12.6814     1.0080
append_frame_single_mixed                   1.6413     1.6281     1.0081
frame_drop_dup_inplace                      3.0013     2.9758     1.0085
groupby_indices                             7.3204     7.2458     1.0103
timeseries_1min_5min_ohlc                   0.6520     0.6450     1.0108
concat_series_axis1                        62.3090    61.6359     1.0109
timeseries_asof_single                      0.0462     0.0456     1.0138
frame_reindex_both_axes                     0.2624     0.2584     1.0158
unstack_sparse_keyspace                     1.2006     1.1787     1.0186
stat_ops_level_frame_sum_multiple           7.1461     7.0128     1.0190
timeseries_large_lookup_value               0.0254     0.0248     1.0210
series_ctor_from_dict                       2.8274     2.7666     1.0220
reindex_frame_level_reindex                 0.8442     0.8254     1.0228
reindex_fillna_backfill                     0.0973     0.0951     1.0228
sort_level_zero                             3.8154     3.7198     1.0257
read_store_table_wide                     178.3879   173.5430     1.0279
merge_2intkey_nosort                       20.8110    20.2428     1.0281
read_store_table_mixed                     32.7878    31.8579     1.0292
dataframe_reindex_columns                   0.2559     0.2486     1.0292
append_frame_single_homogenous              0.2881     0.2799     1.0296
datetimeindex_normalize                     3.1789     3.0859     1.0301
frame_to_string_floats                     52.1017    50.5349     1.0310
index_int64_intersection                   26.6096    25.8025     1.0313
series_drop_duplicates_int                  0.7330     0.7100     1.0324
series_value_counts_int64                   2.1885     2.1093     1.0375
frame_constructor_ndarray                   0.0417     0.0402     1.0385
stat_ops_level_series_sum_multiple          6.6431     6.3889     1.0398
dti_reset_index                             0.1978     0.1894     1.0443
frame_to_csv                              326.8771   312.8140     1.0450
groupby_apply_dict_return                  44.8592    42.9204     1.0452
concat_small_frames                        13.0044    12.4340     1.0459
write_csv_standard                        310.0820   296.3982     1.0462
write_store_table_panel                  4754.1928  4540.0400     1.0472
groupby_multi_series_op                    15.6579    14.9366     1.0483
melt_dataframe                              1.6189     1.5438     1.0486
read_parse_dates_iso8601                    1.3405     1.2780     1.0489
write_store_table_wide                    908.7529   866.2510     1.0491
groupby_multi_cython                       17.1857    16.3653     1.0501
frame_get_numeric_data                      0.0600     0.0570     1.0523
datetimeindex_add_offset                    0.2049     0.1939     1.0566
write_store_table                         441.6649   417.2010     1.0586
read_table_multiple_date                 2447.0708  2302.5630     1.0628
indexing_panel_subset                       0.5616     0.5265     1.0666
match_strings                               0.3960     0.3706     1.0687
groupby_series_simple_cython                5.7912     5.4079     1.0709
frame_ctor_nested_dict_int64              124.0461   115.7539     1.0716
frame_drop_duplicates_na                   21.8943    20.4239     1.0720
frame_reindex_both_axes_ix                  0.3518     0.3272     1.0755
index_datetime_intersection                12.7059    11.7921     1.0775
groupby_multi_python                       62.9150    58.3410     1.0784
replace_fillna                              1.6407     1.5212     1.0786
frame_ctor_nested_dict                     82.6290    76.4521     1.0808
indexing_dataframe_boolean_rows             0.2257     0.2088     1.0809
read_table_multiple_date_baseline        1158.8562  1071.3720     1.0817
join_dataframe_integer_key                  1.8876     1.7371     1.0866
reshape_pivot_time_series                 187.2802   172.2631     1.0872
series_align_irregular_string              69.1018    63.4313     1.0894
write_store_mixed                          34.8185    31.9361     1.0903
series_value_counts_strings                 5.7692     5.2803     1.0926
timeseries_timestamp_tzinfo_cons            0.0206     0.0188     1.0943
reshape_unstack_simple                      2.9168     2.6569     1.0978
read_store_table                           10.5529     9.6076     1.0984
replace_replacena                           1.6949     1.5405     1.1003
series_constructor_ndarray                  0.0106     0.0097     1.1009
frame_drop_dup_na_inplace                   3.0536     2.7255     1.1204
groupby_multi_different_numpy_functions    14.1280    12.5601     1.1248
reshape_stack_simple                        2.3761     2.1098     1.1263
indexing_dataframe_boolean_rows_object      0.4973     0.4413     1.1270
lib_fast_zip_fillna                        16.5020    14.6356     1.1275
groupby_first                               3.4041     3.0132     1.1297
timeseries_asof_nan                        11.6815    10.1902     1.1463
datetimeindex_unique                        0.1927     0.1676     1.1494
timeseries_sort_index                      24.0719    20.9241     1.1504
groupby_sum_booleans                        0.8692     0.7514     1.1567
series_string_vector_slice                330.9171   284.9329     1.1614
groupby_pivot_table                        21.4290    18.3129     1.1702
frame_insert_500_columns                   98.2690    83.2559     1.1803
timeseries_to_datetime_iso8601              5.6211     4.7594     1.1811
frame_fancy_lookup_all                     26.3765    22.2771     1.1840
groupby_simple_compress_timing             40.3659    33.9840     1.1878
query_store_table                           6.2538     5.2541     1.1903
frame_iteritems                             2.5363     2.1235     1.1944
sparse_series_to_frame                    160.5530   131.9690     1.2166
groupbym_frame_apply                       67.0725    54.3806     1.2334
reindex_frame_level_align                   0.8305     0.6723     1.2353
read_store                                  7.3415     5.9335     1.2373
join_dataframe_index_single_key_small      11.3160     9.0686     1.2478
reindex_multiindex                          1.4660     1.1627     1.2609
groupby_multi_size                         35.6657    27.5457     1.2948
sparse_frame_constructor                    6.8283     5.1579     1.3239
timeseries_timestamp_downsample_mean       11.0256     8.1208     1.3577
timeseries_infer_freq                      10.2630     7.5523     1.3589
groupby_last                                4.0580     2.8608     1.4185
```
