Designs presentation tables that read correctly at a glance - numeric alignment, consistent precision, deliberate sort order, unit-labeled headers, and well-placed totals - and delivers a before/after redesign of the reader's table. Use when someone asks "make this table more readable", "how many decimals should I show", "should totals go at the top or bottom", "this report table is a mess", or is preparing tabular data for an exec deck or published report. Do NOT use for designing database tables, keys, and normalization - use database-schema instead; for narrative structure around the numbers - use data-story instead; for assembling the full multi-section document - use formatted-report-writer instead.
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name: Data Table Design
description: Designs presentation tables that read correctly at a glance - numeric alignment, consistent precision, deliberate sort order, unit-labeled headers, and well-placed totals - and delivers a before/after redesign of the reader's table. Use when someone asks "make this table more readable", "how many decimals should I show", "should totals go at the top or bottom", "this report table is a mess", or is preparing tabular data for an exec deck or published report. Do NOT use for designing database tables, keys, and normalization - use database-schema instead; for narrative structure around the numbers - use data-story instead; for assembling the full multi-section document - use formatted-report-writer instead.
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# Data Table Design
A table is not a spreadsheet dump. Every formatting choice either helps or hinders the reader's ability to compare, rank, and interpret - and a misaligned or falsely precise table gets numbers misread in the meetings that matter. The output of this skill is a table a reader can extract the right conclusion from in under ten seconds.
## Operating procedure
### Step 1: Gather inputs
1. The table as it stands (or the raw data), and where it will live: slide, printed report, dashboard, or scrolling web page - the medium changes the density rules in Step 5.
2. The reader's single most likely question. Every subsequent decision serves it. If the owner cannot name the question, that is the first problem to fix.
3. The action the reader takes from the table. Columns that inform no comparison or action are candidates for deletion.
4. Units and the true precision of the data - what the collection method actually supports, not what the export prints.
### Step 2: Set alignment
- Right-align all numeric columns without exception - alignment makes magnitude visible at a glance.
- Left-align text columns.
- Center column headers only when the column is narrow and centering does not visually disconnect the header from its values.
- Never mix alignments within a single column.
- Use tabular (fixed-width) figures where the medium allows; proportional digits break vertical comparison.… install to load the full skill